• ABS Brake Wiring (4 Wheel)
• Air Conditioning
• Airbag SRS system
• Anti Theft System
• Automatic Transmission System (Page 1)
• Automatic Transmission System (Page 2)
• Backup Lighting
• CCD Network
• Central Timer Module
• Charging System
• Instrument Cluster (Page 1)
• Instrument Cluster (Page 2)
• Instrument Cluster Lights
• Courtesy Lights
• Cruise Control
• Engine System (Page 1)
• Engine System (Page 2)
• Engine System (Page 3)
• Exterior lighting (Page 1)
• Exterior lighting (Page 2)
• Grounds (Page 1)
• Grounds (Page 2)
• Grounds (Page 3)
• Headlights
• Headlights w/Quad
• Headlights w/DRL
• Grounds w/Quad and w/DRL
• Heater
• Horn
• Intergrated Module
• Overhead Module
• Power Distribution (Page 1)
• Power Distribution (Page 2)
• Power Distribution (Page 3)
• Power Door Locks with Keyless Entry
• Power Door Locks
• Power Mirrors
• Power Seat
• Power Windows
• Radio
• Radio (Premium)
• Seat Belt
• Starting System
• Warning System
• Wipers

ABS Brake System (4 Wheel)

Air Conditioning Wiring

Air Bag SRS Wiring

Anti Theft System

Automatic Transmission System (Page 1)

Automatic Transmission System (Page 2)

Backup Lighting

CCD Network

Central Timer Module

Charging System

Instrument Cluster (Page 1)

Instrument Cluster (Page 2)

Instrument Cluster Lights

Courtesy Lights

Cruise Control

Engine System (Page 1)

Engine System (Page 2)

Engine System (Page 3)

Exterior Lighting (Page 1)

Exterior Lighting (Page 2)

Grounds (Page 1)

Grounds (Page 2)

Grounds (Page 3)

Headlights

Headlights w/Quad

Headlights w/DRL

Headlights w/Quad and w/DRL

Heater

Horn

Integrated module

Overhead module

Power Distribution (Page 1)

Power Distribution (Page 2)

Power Distribution (Page 3)

Power Door Locks With Keyless Entry

Power Door Locks

Power Mirrors

Power Seat

Power Winodws

Radio

Radio (Premium)

Seat Belt

Starting System

Warning System

Wipers

Our trucks arrived with a "bare minimum" alternator design to get the vehicles off the sales lot. The grid heater configuration along with head lights and a fan blower for heat or defrost on early cold mornings takes the demand for these wimpy alternators to their design limits. Once we begin to "pound or beat" these diodes into forward and reverse current conduction we begin to see changes in the silicon junctions. It is cumulative and in time between hot summer and cold winter conditions our diode bridges become "leaky" and the "ripple" (AC component) becomes excessive and certain electric system devices begin to balk or react strangely with the imposed "ripple" floating on the DC(direct current) rail.

Excellent mil-spec electronic devices or space-bound instruments MUST HAVE bullet proof power supplies. PURE DC hard-core power supplies are normal components and can be built without much effort today. Our alternators and dual batteries ARE the DC supplies for our trucks. The error is budget on Daimler/Chrysler's decision to put these 135 amp alternators into the Cummins platform. 

The standard rule of thumb for all electronic design regarding power supplies is, "If you have a demand of 100 amps maximum in a given system, you build a supply with 50% more headroom minimum. Now, take conditions into consideration...heat, cold and perhaps a poor matched battery in a dual battery (paralleled batteries) storage supply and the occasional "starter" operation (the Cummins starter is INSANE on current demand!) and WE have a real MONSTER to feed!

Boys and Girls...if you want bullet-proof DC, double the available current at idle. Yes...this is correct...go with a 6 phase (twelve diode pack) and a hand-wound "square wire" hairpin-stator. The six-phase stator and companion rotor  will cut the ripple to near zero in conjunction  with proper storage capacity (really good paralleled batteries) you will have the power supply for your Cummins. The "square" wire wind is best for current demand when an "AC field wave-form" is cutting the coil to impose current into the inductive system. It is the cutting edge in design for transformers with high efficiency and LESS HEAT. Heat is "loss" and also destroys the surrounding aspects of the generating device.

BTW...not even Nations builds to these specifications....they buy their upper-end higher current devices from a source in Riverside California.

Just for grins... 1 Amp...what is this? Electronics 101:

Current flow is "electrons" ( remember 5th grade science?) the Atom is composed of three elements the Proton, Neutron and the little Electron flying around the other two elements like an orbiting satellite. It is the "electron" we are interested in when it comes to DC (direct current) when we refer to "current flow" in a circuit.

SO...the question is? When we measure "current flow"  the term Amps is used....how many "electrons" flow through a piece of wire at a given point in "one second" ???

One Amp is (physics term "Coulomb" ) equals 1x10 to the eighteenth power....hence; when you start your mighty Cummins you are transferring 1x10x18 x 600 electrons in order to spin the Beast into run condition ! Take a look at the size of this number ! This is why you need "FAT" wire to allow all those little (minions) electrons to race at the speed of light through the wire to the given load. 

As you can see...current flow is from "negative" to "positive" in our world. The battery has a "positive" terminal and it is "sucking" to become satisfied. It attracts ("sucks") electrons off the frame-rail of your truck "as current flow" in order to spin the armature of the starter motor.

SO..."negative" (electrons) flow towards the "positive" (hole or sucking-action)....seems we have an "upside down" world !!!!

Now this leads us to another interesting Physics observation...you see...lights Do Not Give Off Light ! They suck "dark" and you will notice when a light bulb "burns out" and no longer provides luminescence....we say "it is burned out" however; we now know that is not true!.... IT IS FULL of Dark and we need a new bulb ...Look at the bulb...it's "dark".

Sorry...had to share this funny tid-bit...none the less...our Cummins platforms were not produced with Mil-Spec in mind. Sorry, our ECM and PCM's must be provided "clean" stable DC in order to function correctly. The design guys never considered 6 millivolts  of "ripple" to be critical for converter "lock and unlock" syndrome and yet we see the result and unwanted operational characteristics. 

I build killer DC power supplies for various electronic devices...you need a shop oscilloscope to even see the minor "AC ripple" and as for regulation, from zero to 100 Amps at 14.8 volts there is NO DC drop in voltage. It is like taking and engine from "zero" to "red line" in a heart-beat and you don't even see a fraction of a voltage drop...this is called a "Stiff DC Regulated Supply".

Build your DC Supply...the Cummins platform is a Nobel Beast....feed it a good stiff DC diet with NO sag and Zero ripple and all will be well.

ALSO...guys I lurk around out here...I've seen photos you have all taken "under the hood" of your beloved vehicles...gosh golly!!! The appearance of the battery terminals and cable connectors...it is pretty sad. You can't transfer billions and billions of electrons (with NO heat) through the scum I have viewed. 

Again...No worries...we are all in this together... I share this respectfully as intellectual content with just a touch of humor  

Cheers

What I'm going to describe is a rare event. This is possible with any alternator stock ND or Bosch or even the aftermarket alternators that are bigger amperage output. In a nutshell, at any point, the blue field lead happens to short to ground the entire short is routed back through the PCM. Since the PCM is protected by a shared fuse of 20 amps this means the circuit board fails during these events. There have been two cases of this which is @pepsi71ocean and myself with the same failure. The only difference is mine failed so badly that it burned a hole through the PCM circuit board making the PCM unrepairable. I was forced to replace the PCM completely. 

Diagnostics

You want to start the engine and check the blue for +12V. This +12V power should be present with the engine running. It's tested by using a DVM or test light. If power is not present then the PCM is damaged. The green wire will show a good ground more than likely but this will not work is there is no +12V to the field. This is where you make use of the article for ECM /PCM rebuilders. Make sure to test the alternator and replace it as well.

The Modification

This is based on the W-T ground wire mod. Being the field lead is powered from the PCM and the PCM, ECM and VP44 all share the same 20 amp fuse in slot G of the PDC. This fuse is too large to protect the PCM from a field wire short. This means you would have to purchase a fuse holder and solder in a fuse holder on the blue wire. With the PCM connectors removed from the PCM look at the connector towards the fender, this is connector C3. Pin 25 is the blue wire you can ohm test from end to end to be sure the wire is not broken. Then ohm between the blue wire and ground to verify its not shorted to ground still. Now take the tape near the loom and unwind it. This will give you about another 1 inch of wire. About 2 inches from the loom cut the blue wire. This should give you like 6 inches from the plug end and then a kind of stubby 2-inch wire on the loom end. Now solder in the fuse holder and use shrink tubing over your solder joints. 

With a bit of neat folding of the wire you should be able to loom the fuse holder into the loom again.

I know that @IBMobile did the load testing of the field lead and suggests a 7.5 amp fuse. I'm going to do the testing with a 5 amp fuse. 

As for protection of the alternator on the charge lead, I opted to purchase a resetable 150 amp breaker. I know the factory alternator fuse was 140 amps. I know that the alternator will not produce more than 135 amps of charging current. I know the breaker is not there for protection the alternator for excessive charge current. The breaker is there just in case there is a dead short on the diode pack. If the short was good enough it could light that 6 gauge cable on fire. So having an exact 140 amp breaker is not required. The other thing I was reading up on was the breakers tend to trip prematurely because of underhood temperatures. I wanted to be just that little bit bigger that it does not trip the breaker because the alternator is already at full current charging on a hot day like jump starting another vehicle. 

Fallout, External Regulator users

As for all you as fallout from this problem you typically were doing the external voltage regulator because of the PCM failure. I'm going to suggest that you consider doing the PCM repair and doing this mod and getting away from the external voltage regulator. 

Ok, recent thread on here drove me past the point of looking at wiring diagrams and giving direction. Somethings are just easier explained with pictures and tested against a known good working system. 

So in an effort to help others, I tore my own truck apart in the dark outside in Alaskan November temperatures with a few simple test tools, a head lamp and an IPhone camera so bare with me if the pictures aren't the greatest.

I do prefer that testing be done test light when possible. A meter is useful tool but if you don't 100% completely know how to use/test with it you can easily be lead in the wrong direction. Just throwing that out there from 11 years now of turning wrenches for a living. See it happen all the time. No current flow no voltage drop. Testing circuits when they are loaded is best.

First of all you are going to have to look at a diagram, going to make you.

On this diagram we can see
- Powertrain Control Module or PCM - Controls Alternator Fields (Turns the alternator on/off)
- Power Distribution Center or PDC - Fuse box under the hood
- The Generator or Alternator - If you need this explained.... 

1. There is a Black/Grey Wire between the Gen/Alt and the PDC which contains the 140amp fuse and then a red wire to the battery. This is the large charge wire that electricity flows from the Gen/Alt to the 140amp fuse in the PDC and onto the battery. This is the large wire on the large stud on your Gen/Alt and you should have battery voltage or alternator output voltage on this stud. Check the fuse if you don't, or wires associated with that circuit.

2. Now into the meat of things, there are two wires from the PCM to the Alternator.
- Here is the two pin plug that plugs into the back of the Alternator, notice the Green and Dark Blue Wires.

- The dark blue wire is the voltage supply to the Generator fields. Meaning this is a positive wire and should have 12V on a meter or light a test light like this when the test light is hooked to battery negative as in the picture. (A meter would be the same with the negative lead) Engine MUST be running, key on engine off does not work for this test. *For demonstration purposes pictures are taken with engine off so the test light is not lit in these photo's.*

- The green wire is the control wire, meaning the PCM grounds this wire to turn on or off the alternator fields (DO NOT THINK YOU CAN JUST JUMP THIS TO GROUND FOREVER TO BYPASS THE PCM IT WILL FRY LOTS OF STUFF BECAUSE THE ALTERNATOR WILL BE FULL FIELDED TO 16+ VOLTS) This is a ground circuit so with the truck running a test light or meter hooked to battery positive should show 12V or light like this. 

If you have power on the blue wire while the engine is running and can hook 12v to ground on the green wire while the engine is running and voltage on the large stud your alternator is bad, but if you don't have one of the other.........

This is where the PCM lives behind your air filter box, notice I removed mine for better access, TURN THE KEY OFF before disconnecting

The connector closest to the passenger side is the Grey C3 connector. The Connector in the middle is the White C2 connector. Reference the wiring diagram at the PCM. We are concerned with pin 25 in the Grey C3 connector as it is the opposite end of the dark blue wire at the alternator. We are also concerned with pin 10 of the White C3 connector as it is the opposite end of the green wire at the alternator.

NOTE - The connectors have a locking tab on the top and bottom, do not force, use shop air if need to blow out dirt so the locks release and you can unhook the connectors.
Noticed the pins are numbered, double and triple check your are on the correct pin when testing.
Grey C3 shown here

White C2 shown here

Now using your meter set it to continuity or resistance test and check between pin 25 in the Grey C3 connector and the BLUE wire pin at the alternator plug. There should be a connection between these two pins.

Next test the Pin 10 of the White C2 connector to the GREEN wire pin at the alternator plug. There should be a connection between these two pins.

Meters vary from make to make as to what they will read (some beep) when showing continuity vs an open circuit. Simple test is to simply look at what the meter says when the leads are not touching each other..... like this.

VS

With the leads touching each other. (no resistance, good connection)

This is what you want to see when testing both of your wires between the PCM and Alt plug

Now if these wires both test good, more than likely your PCM is bad. To be 100% positive it is the PCM, I would pull the plastic cover off of the C2 and C3 connectors and back probe the blue and green wires and see if you have 12Vs that way, this would eliminate the entire harness and test only the PCM.

How you go about fixing the issue is up to you. With the manual transmission trucks that is all these two wires do. BUT with the Automatic trucks notice in the diagram that the BLUE wire also powers the transmission relay through a splice. 

I'll try to update this with information as to PCM repair or external voltage regulator solutions. 

Now if these wires both test good, more than likely your PCM is bad. To be 100% positive it is the PCM, I would pull the plastic cover off of the C2 and C3 connectors and back probe the blue and green wires with the harnesses plugged in and see if you have 12Vs that way, this would eliminate the entire harness and test only the PCM.

How you go about fixing the issue is up to you. With the manual transmission trucks that is all these two wires do. BUT with the Automatic trucks notice in the diagram that the BLUE wire also powers the transmission relay through a splice. 

I'll try to update this with information as to PCM repair or external voltage regulator solutions. Hope it answers some questions.

Engine running for testing at the plug. Key off before unhooking PCM.

Exposed to outside elements, heat, vibration and potential corrosion, moving it inside was most practical.

Non Dodge/ midrange applications of Cummins 5.9 24V ISB’s all have their TPS/APPS inside the cab, mounted on the pedal assembly. So nothing is changing on the apps operation, just moving it.

This mod does not works on trucks that are auto/use vacuum for cruise. The auto trans kickdown cable is attached to the bellcrank assembly. As with the vacuum solenoid setup too so if you can live without them then it will work.

Parts needed:

699-5101 pedal assembly

(2x) 6 pin Duetsch connectors kits

Zip ties

Grommet

6’ of 6 wire harness

Tools needed:

Duetsch connector terminal pliers

Wire strippers

Making the mount will be up to you. I can show you pictures on how I made mine but it’s just a one off. Either way you need to mount it inside. 

First, disconnect the 6 pin Duetsch connector from the apps, remove the bellcrank assembly from the cylinder head. Cut off the cable and discard. The oem pedal assembly will need to be removed and the oem mount has a pivot pin on the bottom that’ll twist out with some channel lock pliers.

Once you mount your new pedal to the mount and it’s installed all that is needed is how to control via ecm. So a 6 wire jumper harness is needed. I would HIGHLY recommend removing and tossing the apps that comes supplied with the new pedal and install your current one in its place. I can’t guarantee its quality.

If you need an apps, a Williams Control 131973 or 133284 will work perfectly (Timbo is just a repackaged WC). Available from any oem truck dealer (I.e. Kenworth or Freightliner).

On your engine side of your harness you need to make a 6 pin male Duetsch connector. Ensure you new connector kits have the locks in them, some kits do not come with them for some reason. YouTube or Google can provide a video on how to use Duetsch connector pliers, they’re super easy to use.

Using the hole in firewall that the original pull cable went through install a grommet to prevent rubbing and feed your harness through. If you prefer to drill a hole the same size of the connector body you’ll need a 7/8” drill bit.
**It’s easier to make the harness, THEN crimp the new terminals on after feeding it through the oem firewall hole for a cleaner look.**

Cut your 6 wire harness to length and crimp on the terminals, install the connector body and plug it in. Theoretically the engine doesn’t know where the apps is so it will work. Make sure you mate up each wire in its proper spot on each connector, if you mess them up a CEL will come on/non functionality of the apps.

Secure the harness to various points with zip ties so it’s rigid. This provides a clean look and more room in the engine compartment for future servicing.

Start the engine and test. Throttle response should be crisp since there is no cable anymore that has slack as it wore.

Description

The Accelerator Pedal Position Sensor (APPS sensor) assembly is located at the top-left-front of the engine (Fig. 4). A plastic cover is used to cover the assembly. The actual sensor is located behind its mounting bracket (Fig. 5).

Operation

The Accelerator Pedal Position Sensor (APPS Sensor) is a linear potentiometer. It provides the Engine Control Module (ECM) with a DC voltage signal proportional to the angle, or position of the accelerator pedal. In previous model years, this part was known as the Throttle Position Sensor (TPS). Diesel engines used in previous model years used a mechanical cable between the accelerator pedal and the TPS lever. Linkage and bellcranks between the TPS cable lever and the fuel injection pump were also used. Although the cable has been retained with the Accelerator Pedal Position Sensor (APPS sensor), the linkage and bellcrank between the cable lever and the fuel injection pump are no longer used. The Accelerator Pedal Position Sensor (APPS Sensor) is serviced (replaced) as one assembly including the lever, brackets, and sensor. The Accelerator Pedal Position Sensor (APPS Sensor) is calibrated and permanently positioned to its mounting bracket.

Removal

The Accelerator Pedal Position Sensor (APPS Sensor) is serviced (replaced) as one assembly including the lever, brackets, and sensor. TheAccelerator Pedal Position Sensor (APPS) is calibrated to its mounting bracket. The Accelerator Pedal Position Sensor (APPS Sensor) assembly is located at the left front of the engine below plastic cable/lever/linkage cover (Fig. 6).

Front with cover removed

Rear of APPS sensor

1. Disconnect both negative battery cables at both batteries.
2. Remove cable cover. Cable cover is attached with 2 Phillips screws, 2 plastic retention clips, and 2 push tabs. Remove 2 Phillips screws and carefully pry out 2 retention clips. After clip removal, push rearward on front tab, and upward on the lower tab for cover removal.
3. Using finger pressure only, disconnect end of speed control servo cable from throttle lever pin by pulling forward on connector while holding lever rearward.DO NOT try to pull the connector off perpendicular to lever pin. The connector will be broken.
4. Using two small screwdrivers, pry throttle cable connector socket from throttle lever ball. Be very careful not to bend throttle lever arm.
5. Disconnect transmission control cable at lever arm (if equipped). Refer to 21, Transmission.
6. Squeeze pinch tabs on speed control cable and pull cable rearward to remove from cable mounting bracket.
7. Squeeze pinch tabs on the throttle cable and pull cable rearward to remove from cable mounting bracket.
8. If equipped with an automatic transmission, refer to 21, Transmission for transmission control cable removal procedures.
9. Disconnect wiring harness clips at the bottom of the bracket.
10. Remove 6 mounting bolts and partially remove Accelerator Pedal Position Sensor (APPS sensor) assembly from the engine. After the assembly is partially removed, disconnect the electrical connector from the bottom of the sensor by pushing on connector tab.
11. Remove Accelerator Pedal Position Sensor (APPS sensor) assembly from the engine.

Installation

The Accelerator Pedal Position Sensor (APPS sensor) is serviced (replaced) as one assembly including the lever, brackets, and sensor. The Accelerator Pedal Position Sensor (APPS sensor) is calibrated to its mounting bracket. The Accelerator Pedal Position Sensor (APPS Sensor) assembly is located at the left front of the engine below plastic cable/lever/linkage cover (Fig. 6).

1. Snap electrical connector into the bottom of the sensor.
2. Position Accelerator Pedal Position Sensor (APPS Sensor) assembly to the engine and install 6 bolts. Tighten bolts to 12 N·m (105 in. lbs.) torque.
3. Connect wiring harness clip (Fig. 8) at the bottom of the bracket.
4. If equipped with an automatic transmission, refer to Group 21, Transmission for transmission control cable installation procedures.
5. Install speed control cable into the mounting bracket. Be sure pinch tabs (Fig. 7) have secured cable.
6. Install throttle cable into the mounting bracket. Be sure pinch tabs (Fig. 7) have secured cable.
7. Connect throttle cable at the lever (snaps on).
8. Connect speed control cable to the lever by pushing cable connector rearward onto lever pin while holding lever forward.
9. Install cable cover.
10. Connect both negative battery cables to both batteries.

ECM & APPS Calibration

WARNING! Any time the batteries are disconnected, batteries ran dead, ECM disconnected, APPS disconnected, APPS replaced the APPS calibration procedure MUST be done again to reset the APPS idle and WOT limits. If the calibration is not done error codes and other issues must occur.

Disconnect the batteries and leave disconnected for at least 30 minutes. Now reconnect the batteries.

Turn the key to ON position. Without starting the engine, slowly press throttle pedal to the floor and then slowly release. This step must be done (one time) to ensure accelerator pedal position sensor calibration has been learned by ECM. If not done, possible DTC’s may be set.

This device can also prevent barking by using the same logic in reverse.  

What you will need for this is

- Arduino Uno with a button / LCD shield http://www.ebay.com/itm/UNO-R3-BOARD-LCD-BUTTON-SHIELD-CABLE-ARDUINO-COMPATABLE-PREPROGRAMMED-/322124430521?hash=item4b001cbcb9:g:ulAAAMXQpPhTlIkP

- Deutsch dt 6 plugs http://www.ebay.com/itm/321335296062?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

- ~30" of 14 - 16 gauge wire.  More or less to remote mount the unit in cab

- 12v power source for arduino, I would suggest usb car charger to usb B plug

Connecting the Unit,

Stack the arduino with the button shield, The pins should line up

The TPS input from the apps ( white wire) plugs into A0 on the arduino board, and should be pin 3 on the female end of the DT -6 plug that plugs into the apps sensor.

The TPS output from the arduino ( blue wire) plugs into pin 3 on the arduino, and should be pin 3 on the male end of the dt-6 Plug that plugs into the OEM wire that leads to the ecm.

All other wires between the DT-6 plugs are pass through wires, IE; pin 1 to pin 1

Upload this Code to the arduino using a USB cable and the arduino software

unplug the OEM dt-6 connector from the APPS sensor, plug in the arduino pig tail to the apps and the OEM dt-6 plug that leads to the ecm.

Use,

Use the far left button to set the buffer for increasing throttle, then use the up and down to increase or decrease between 1 and 2000 ms.

To set the buffer for decreasing TPS use the 2nd to left button to set the mode, then use the up and down button to increase or decrease between 1 and 500 ms.  

to see the inputted TPS vs the Outputted TPS use the 2nd to right button

"TPS In" is what the driver commanded for a position, TPS Out is what the arduino outputted to the ecm.  You should see the output follow the input.

Description

The Chrysler Collision Detection (also referred to as CCD or C2D ) data bus system is a multiplex system used for vehicle communications on many Chrysler Corporation vehicles. Within the context of the CCD system, the term “collision“ refers to the system’s ability to avoid collisions of the electronic data that enters the data bus from various electronic control modules at approximately the same time. Multiplexing is a system that enables the transmission of several messages over a single channel or circuit. Many Chrysler vehicles use this principle for communication between the various microprocessor based electronic control modules.

Many of the electronic control modules in a vehicle require information from the same sensing device. In the past, if information from one sensing device was required by several controllers, a wire from each controller needed to be connected in parallel to that sensor.
In addition, each controller utilizing analog sensors required an Analog/Digital (A/D) converter in order to “read“ these sensor inputs. Multiplexing reduces wire harness complexity, the sensor current loads, and controller hardware because each sensing device is connected to only one controller, which reads and distributes the sensor information to the other controllers over the data bus. Also, because each controller on the data bus can access the controller sensor inputs to every other controller on the data bus, more function, and feature capabilities are possible.

In addition to reducing wire harness complexity, component sensor current loads and controller hardware, multiplexing offers a diagnostic advantage. A multiplex system allows the information flowing between controllers to be monitored using a diagnostic scan tool. The Chrysler system allows an electronic control module to broadcast message data out onto the bus where all other electronic control modules can “hear” the messages that are being sent. When a module hears a message on the data bus that it requires, it relays that message to its microprocessor. Each module ignores the messages on the data bus that are being sent to other electronic control modules.

With a diagnostic scan tool connected into the CCD circuit, a technician is able to observe many of the electronic control module function and message outputs while; at the same time, controlling many of the sensor message inputs. The CCD data bus, along with the use of a diagnostic scan tool and a logic based approach to test procedures, as found in the Diagnostic Procedures manuals, allows the trained automotive technician to more easily, accurately and efficiently diagnose the many complex and integrated electronic functions and features found in today’s vehicles.

Operation

The CCD data bus system was designed to run at a 7812.5 baud rate (or 7812.5 bits per second). In order to successfully transmit and receive binary messages over the CCD data bus, the system requires the following:

• Bus (+) and Bus (–) Circuits

• CCD Chips in Each Electronic Control Module

• Bus Bias and Termination

• Bus Messaging

• Bus Message Coding

Following are additional details of each of the above system requirements.

Bus Circuits

The two wires (sometimes referred to as the “twisted pair”) that comprise the CCD data bus are the D1 circuit [Bus (+)], and the D2 circuit [Bus (–)]. The "D" in D1 and D2 identify these as diagnostic circuits. Transmission and receipt of binary messages on the CCD data bus are accomplished by cycling the voltage differential between the Bus (+) and Bus (–) circuits.

The two data bus wires are twisted together in order to shield the wires from the effects of any Electro-Magnetic Interference (EMI) from switched voltage sources. An induced EMI voltage can be generated in any wire by a nearby switched voltage or switched ground circuit. By twisting the data bus wires together, the induced voltage spike (either up or down) affects both wires equally. Since both wires are affected equally, a voltage differential still exists between the Bus (+) and Bus (–) circuits, and the data bus messages can still be broadcast or received. The correct specification for data bus wire twisting is one turn for every 44.45 millimeters (1 3⁄4 inches) of wire.

CCD Chips

In order for an electronic control module to communicate with the CCD data bus, it must have a CCD chip (Fig. 5). The CCD chip contains a differential transmitter/receiver (or transceiver), which is used to send and receive messages. Each module is wired in parallel to the data bus through its CCD chip.

The differential transceiver sends messages by using two current drivers: one current source driver, and one current sink driver. The current drivers are matched and allow 0.006 ampere to flow through the data bus circuits. When the transceiver drivers are turned On, the Bus (+) voltage increases slightly, and the Bus (–) voltage decreases slightly. By cycling the drivers On and Off, the CCD chip causes the voltage on the data bus circuit to fluctuate to reflect the message.

Once a message is broadcast over the CCD data bus, all electronic control modules on the data bus have the ability to receive it through their CCD chip. Reception of CCD messages is also carried out by the transceiver in the CCD chip. The transceiver monitors the voltage on the data bus for any fluctuations. When data bus voltage fluctuations are detected, they are interpreted by the transceiver as binary messages and sent to the electronic control module’s microprocessor.

Bus Bias And Termination

The voltage network used by the CCD data bus to transmit messages requires both bias and termination. At least one electronic control module on the data bus must provide a voltage source for the CCD data bus network known as bus bias, and there must
be at least one bus termination point for the data bus circuit to be complete. However, while bias and termination are both required for data bus operation, they both do not have to be within the same electronic control module. The CCD data bus is biased to approximately 2.5 volts. With each of the electronic control modules wired in parallel to the data bus, all modules utilize the same bus bias. Therefore, based upon vehicle options, the data bus can accommodate two or twenty electronic control modules without affecting bus voltage.

The power supplied to the data bus is known as bus biasing. Bus bias is provided through a series circuit. To properly bias the data bus circuits, a 5 volt supply is provided through a 13 kilohm resistor to the Bus (–) circuit (Fig. 6). Voltage from the Bus (–) circuit flows through a 120 ohm termination resistor to the Bus (+) circuit. The Bus (+) circuit is grounded through another 13 kilohm resistor. While at least one termination resistor is required for the system to operate, most Chrysler systems use two. The second termination resistor serves as a backup (Fig. 7). The termination resistor provides a path for the bus bias voltage. Without a termination point, voltage biasing would not occur. Voltage would go to 5 volts on one bus wire and 0 volts on the other bus wire. The voltage drop through the termination resistor creates 2.51 volts on Bus (–), and 2.49 volts on Bus (+). The voltage difference between the two circuits is 0.02 volts. When the data bus voltage differential is a steady 0.02 volts, the CCD system is considered “idle.” When no input is received from any module and the ignition switch is in the Off position for a pre-programmed length of time, the bus data becomes inactive or enters the ”sleep mode.” Electronic control modules that provide bus bias can be programmed to ”wake up” the data bus and become active upon receiving any predetermined input or when the ignition switch is turned to the On position.

Bus Messaging

The electronic control modules used in the CCD data bus system contain microprocessors. Digital signals are the means by which microprocessors operate internally and communicate messages to other microprocessors. Digital signals are limited to two states, voltage high or voltage low, corresponding to either a one or a zero. Unlike conventional binary code, the CCD data bus systems translate a small voltage difference as a one (1), and a larger voltage difference as a zero (0). The use of the 0 and 1 is referred to as binary coding. Each binary number is called a bit, and eight bits make up a byte. For example: 01011101 represents a message. The controllers in the multiplex system are able to send thousands of these bytes strung together to communicate a variety of messages. Through the use of binary data transmission, all electronic control modules on the data bus can communicate with each other. The microprocessors in the CCD data bus system translate the binary messages into Hexadecimal Code (or Hex Code). The hex code is the means by which microprocessors communicate and interpret messages. When fault codes are received by the DRBIII scan tool, they are translated into text for display on the DRBIII screen. Although not displayed by the DRBIII for Body Systems, hex codes are shown by the DRBIII for Engine System faults. When the microprocessor signals the transceiver in the CCD chip to broadcast a message, the transceiver turns the current drivers On and Off, which cycles the voltage on the CCD data bus circuits to correspond to the message. At idle, the CCD system recognizes the 0.02 voltage differential as a binary bit 1. When the current drivers are actuated, the voltage differential from idle must increase by 0.02 volt for the CCD system to recognize a binary bit 0. The nominal voltage differential for a 0 bit is 0.100 volts. However, data bus voltage differentials can range anywhere between 0.02 and 0.120 volts.

Bus Failure

The CCD data bus can be monitored using the DRBIII scan tool. However, it is possible for the data bus to pass all tests since the voltage parameters will be in “range“ and false signals are being sent. There are essentially 12 “hard failures“ that can occur with the CCD data bus:

• Bus Shorted to Battery

• Bus Shorted to 5 Volts

• Bus Shorted to Ground

• Bus (+) Shorted to Bus (–)

• Bus (–) and Bus (+) Open

• Bus (+) Open

• Bus (–) Open

• No Bus Bias

• Bus Bias Level Too High

• Bus Bias Level Too Low

• No Bus Termination

• Not Receiving Bus Messages Correctly

Refer to the appropriate diagnostic procedures for details on how to diagnose these faults using a DRBIII scan tool.

Bus Failure Visual Symptoms & Diagnosis

The following visible symptoms or customer complaints, alone or in combination, may indicate a CCD data bus failure:

• Airbag Indicator Lamp and Malfunction Indicator Lamp (MIL) Illuminated

• Instrument Cluster Gauges (All) Inoperative

• No Compass Mini-Trip Computer (CMTC) Operation

Wiring Diagrams

 Replacing         Replacing Diodes and Brushes in a Denso Alternator

Remove 1the 0mm nut at the B+ post, the three 8mm nuts and the 8mm head screw.  You can use a small screwdriver and gently pry and lift the cove off.  The diodes and brushes are now exposed.   

 Remove the dust cover and four screws that hold in the brush pack assembly, lift assembly out.

 Remove the four Philip head screws that hold the diode/rectifier bridge in, lift diode/rectifier bridge out.

Remove the one screw holding the brush pack to the brush pack assembly.

 Clean the slip rings with 400 grit wet/dry sandpaper.

Assemble with new diode/rectifier bridge and brushes by reversing the disassembly steps.  When installing the new brushes try holding them into the housing with a small pocket screwdriver or a feeler gauge while sliding over the slip rings.   When installing the rear metal cover do not over tighter the 10mm nut for the B+ Insulator.  It will crack and or brake if over tightened.   

Prepared by: J. Daniel Martin / Martin’s Mobile Maintenance

AKA:  IBMobile

11/18/2017

I'm doing this write-up in case anyone runs into the problem I did and they don't want to buy a new or find another style alternator. After I bought the diode replacement and tried to install it I realized that it was slightly different from mine. Note: The new lead is smaller in diameter and shorter than the old lead.

Here is a link on how to take the alternator apart written by IBMobile. If yours is like mine and the lead comes off the side the B+ post nut sizes will be a 13mm but the steps will be the same.

Tools required for modification:

* Small cut off wheel or Air saw

* Ball-peen hammer

* Small files

* Drill and bits

Hardwear required:

Two M6-1.0 nuts

 The original diode pack has the lead coming off the side sticking through 2 tabs. 

 The new diode lead sits on top of one of the stud.

Take a small cut off wheel or air saw and cut roughly where the sharpie mark is. 

I cut a little too much off but this is what it should look like. 

Drill 2 holes left of the letter B for the lead to stick through. Then use a small file to make the hole bigger. 

Once you can see the small U shape around the bottom of the Lead where the insulator sits, take a ball-peen hammer and bend down the metal around it so it sits flat. Youll need to trim the hole big enough that the back of the original lead insulator fits through it. 

Now you need to take the old lead insulator and cut out a piece for the cable to sit lower on the lead. You'll need to do this on the same side but opposite end of the flat part of the U shape. You'll also need to take a 7/16 drill bit and drill a little of the center out so the first nut you screw on can sit further down and the cable lead can sit flush on top of the nut and plastic insulator. 

Put everything back together and install the Alternator. Put the insulator on and tighten the first nut down. This will hold the insulator in place. Next, install the cable lead and next nut. The cable should stick out of the notch you cut. Since the diode lead is shorter there won't be much of the threads sticking out after the 2nd nut is put on.  

Signs / Symtoms

Just noticed today that the oil pressure is way high while driving and not really moving even upon reaching operating coolant temperature. Driving oil pressure at low throttle is 60-70 PSI at full temperature and idling is right around 60 PSI. Here's the oil pressure gauge, full operating temperature while idling...

Even before starting, the oil pressure gauge shows 40 PSI, then after start up right to the 60-70 mark and doesn't move much. I'm hoping this is just the sending unit and not a bearing or electrical problem.

Just got some codes on the dash...
p0523
p0522

Replacing The Oil Pressure Sensor

Replaced the oil pressure sensor today and the in-dash gauge is back to normal. Idle pressure at full coolant temperature is back below 40 PSI, 0 pressure before start up, and the oil pressure needle moves in correlation with the throttle. Still have the codes but I think I read somewhere they will go away once the truck gets driven a while. Did an oil change too but the oil pressure sensor has to be the culprit, I'm pretty sure it was the factory oil pressure sensor because the VOID sticker was still on the ECM harness and it had not been touched. New oil pressure sensor was $90 from the local Cummins place, new part # 4326849. Oil pressure sensor is located under the fuel filter and ECM harness on the driver's side.

Quick Write Up

1. Disconnect 2 negative battery cables.

2. Remove two 10mm bolts holding fuel filter housing to manifold cover and push housing aside.

3. Remove one 4mm allen bolt from ECM harness and pull back harness.

4. If original unit, use a 32mm double deep socket to remove oil pressure sensor (old part# 3408428).

5. Use 1-1/16 double deep socket to install new oil pressure sensor (new Cummins part# 4326849).

6. Torque manifold/fuel housing bolts to 18 ft-lbs.


3 prong

New sensor is the smaller of the two...made in mexico

You can see the ECM harness pulled away and the oil pressure sensor/harness below it.

Installing this bypass will allow you to manually control if and for how long you want to run the grid heaters when the ECM is commanding the grid heaters on.  This will reduce the load on the alternator/charging system and in turn reduce the harmful AC voltage.  This bypass will also keep the fault codes P0380 Intake Air Heater Relay #1 Control Circuit and P0382 Intake Air Heater Relay #2 Control Circuit from being set.

Parts needed:

1.  2 micro relays, terminal 87 (5) normally open (NO) with suppressor                                                                                                                

2.  2 5 watt / 20 ohm resistor

3.  1 single pole single throw switch (spst)

4.  2 male bullet and 2 female bullet connectors

5.  2 ring terminals

7.  Rosin core solder

6.  10 female quick connect terminals

8.  Heat shrink

9.  ¼” protective wire cover

10. Electrical tape

12. Optional    3 ATC fuse holders with 2 amp fuse

13. Something to mount the relays and resistors on.

14. 5 or more  6” zip ties

          Micro relay

Putting it together

To mount the relays, resistors and fuses I used part of a used relay mount from a Volvo that I found.  It was cut and modified to fit the parts.  

I didn’t want to cut the wire harness at the fire wall to access the solenoid trigger wires, yellow/black and orange/black, that goes from the Engine Control Module (ECM) to the grid heater control solenoids.  I ran two wires to each solenoid connecting to the trigger wires with the male bullet connectors.  This sent the trigger signal back to the control relays at terminal 30 (3).  Two more wires were run from terminal 87 (5) of the control relay back to terminal 86 of the grid heater solenoids and connected the wires with the female bullet connectors.

 You can cover the wires from the firewall to the solenoids with the ¼” protective wire cover.

Written by:

J. Daniel Martin, Martin’s Mobile Maintenance

AKA IBMobile

12/21/2018

Suggested Parts List

1 Standard Motor Parts starter solenoid SS-598 (bypass solenoid)

1 automotive on/off switch DC rated (your choice of style)

1 ATC fuse holder or fuse block (needed if not using fuse in PDC)

1 5amp fuse

13” 6AWG wire cable

5’ 18AWG wire red

5’ 18AWG wire blue

3’ 18AWG wire black

2 6AWG 5/16” copper wire ring terminal

3 22-18 AWG #10 ring terminal

2 #10X32X3/4” screw

2 #10X32 nut

4 #10 washer

4-5” of heat shrink (for the 8AWG cable terminals)

5’ ¼” plastic split wire loom

1 pack of 5-7” plastic ties

1 roll rosin core solder

Putting It Together

Disconnect both batteries; remove left (driver’s side) battery and battery tray.  On the side of the battery tray fit the bypass solenoid and mark holes to be drilled; you may have to grind one side of the bypass solenoid mounting bracket to have it fit flush on the side of the battery tray.   Drill 2 holes, 13/64”-7/32”, where marked on battery tray and mount the bypass solenoid with the #10 screws and nuts as shown below. 

Note: the bypass solenoid is grounded through its body so a black ground wire, with a #10 ring terminal at each end, is attached to one of the mounting screws and the other end grounded to the body.  Reinstall the battery tray.

Left battery tray with solenoid attached.

Find a place in the cab where the switch type you chose will fit and be readily accessible.   We used a rocker switch mounted in the kick panel below the steering column.   For power you can tap into the fuse box on the left side of the dash.  Find a terminal that has power only when the ignition key is in the on position.   This is where you can add an ATC fuse holder with a 5amp fuse.  Connect one end of the red wire to the fuse holder and the other end to the switch.  Connect the blue wire to the other switch terminal and run it through the rubber grommet in the fire wall and with a #10 ring terminal connect it to the bypass solenoid terminal marked S; cover with ¼ “ split wire loom. 

Make up the 6AWG cable (an 8AWG cable will work also) with the 5/16” copper ring terminals and heat shrink.   I solder my cable ends on using a small butane torch but you can use a large cable end crimper.   Be sure to index the orientation of the cable ends to the cable before attaching them so the ring terminals fit squarely on to the battery and solenoid.

The cables for the grid heat solenoid and battery power can now be attached to the bypass solenoid; the battery power cable to the firewall side of the bypass relay and the cables for the heater solenoid to the other side; reinstall the battery, connect all the terminals and reset the apps.    

                Left battery tray installed with bypass solenoid.  Notice position of the cables.

Note: I have experienced a P1291” No temperature rise seen from intake heaters” when the temperature is below 35°F and the heaters are turned off right after starting the engine.   I suggest leaving them on when first starting in cold weather for a minute or two.

Note: It was first suggested to use an SS-581 starter solenoid, this solenoid does not have a protective diode in it and may cause a voltage spike that could damage sensitive electronic components.  A SS-598 solenoid should be used in its place.    

This was installed with the help of JAG1 on his 2001 Ram 2500 diesel utility box work truck.

Written by:

 J. Daniel Martin

AKA IBMobile 

7/6/2019

Extensive review of many posts regarding TC lock unlock, the rerouting methodes, the add on filters for APPS and last, but not least,...the "tin-foil hat" brigade. I do realize that each individual or company that contributed to the vast amount of information on the web had good intentions and I must acknowledge that some of the procedures caused me to closely examine what these people were trying to do. I believe it is well known that even a blind mouse occasionally finds a morsel of cheese.

Again, as it is well known @Mopar1973Man  was the only entity who positively identified the instigating source of this key issue. My entry today is not about alternators...it is about what Daimler/Chrysler did in regard to production of these Cummins powered platforms and the complete disregard of common sense Electronic Engineering.  Please note, this applies to automatic and manual transmissions as each platform is plagued in the same manor with different quirks. 

This Blk/Tan #8 gage wire is quite critical in the scheme of things. It is contained within a 1" plastic conduit passing along the front of the engine. It contains water temp sensor leads, air conditioning leads, alternator/PCM leads and the #6 gage alternator charge line to the PDC. This #8 gage Blk/Tan passes over the top/backend of the alternator and is "eventually" connected to the Auxiliary Battery (passenger side) negative terminal.

This snapshot of the Factory Service manual documents "four critical ground leads" that are "spliced" in an unconventional method.

This photo depicts the three #18 gage wires and the single #14 gage wire entering the shrink-tubing where the "crush-splice" occurs. This bundle exits the large plastic conduit below the VP44

This again is a most disturbing depiction of the Daimler/Chrysler method of splicing critical ground leads and then routing this across the top of the alternator and "eventually" bringing this to ground reference. 

This photo depicts where this #8 gage Blk/Tan first connects on the way to "eventual" ground...yes this is the Auxiliary Battery tray connector. Please note: it is spliced again and joins the PCM circuit board grounds...which are critical in their own nature...and "eventually" terminate at the negative post of the Auxiliary Battery's negative terminal.  

This photo is very interesting, it is the Factory Service manual and the assembly line documentation follows this as a road map in the matrix during production. Please NOTE the title "NAME" to each battery...I looked at this for a considerable amount of time before I realized the assembly line coordinators tried to work with the documentation from the Engineering Staff to "make it as it looks"...Could this single oversight be the reason of a four foot ten inch critical ground wire combination traveling the distance to "EVENTUALLY" terminate at ground? From a basic engineering standpoint regarding ground...you "NEVER CHOOSE THE PATH OF EVENTUAL GROUND" !!! 

It is to be the shortest and most concise connection in reference to ground...this is biblical in ALL ELECTRONICS...including pickup trucks.  !

Here is the Factory Service manual documenting the PCM circuit board reference ground starting as a pair of #14 gage wires being spliced into a #10 gage bundle and arriving at the Auxiliary Battery through another connector that joins a #8 gage wire that is "splice-joined" under plastic conduit in a Y configuration joining the rouge #8 gage "after passing over the alternator" traversing the entire engine compartment from the driver side of the vehicle. Seriously 

I have been drinking excessively, most recently, due to the nature of this blatant discovery.   

This is the hidden Y splice at the Auxiliary Battery where the "mess" EVENTUALLY terminates for ground reference.

This photo shows the correct "HOLE" of where to apply ground for the VP44, ECM and the PDC...note the logical location

It took a little research to find the size and proper thread-pitch.

Metric M5 with a 5/16" hex head is perfect

This is where you apply a fresh "quality" #6 gage ground and terminate this at the Main Battery negative post on the drivers side for absolute ground reference for the VP44 and ECM 

This is a very short and concise reference to ground.

This is the corrected procedure for a rather critical ground.

The two largest wires originally contained within the 1 inch conduit are no longer present and located well away from the alternator.

My alternator B+ "charge" line is now a #4 gage line directly connected to the Auxiliary Battery and when my new battery terminals arrive and they are secured, I'll provide photos of a completed Master Power Supply System within this engine bay. 

With these corrections, I would hypothesize that a poor ripple specification on a given alternator would be overcome by the immense capacitance of the parallel batteries and would become less prone to causing the dreaded TC lock/unlock for automatics and cruise-control abnormalities for the manual transmission platforms. 

The #8 gage Blk/Tan passing over the alternator as an "EVENTUAL" ground is gone...the PCM, ECM, VP44 and the PDC are now grounded in accordance of standard Electronic Engineering practices.

Respectfully

W-T

Anyways, I did some quick looking and decided to upgrade to the famed Group31's. And the results are nothing less then amazing.

So not only did the truck start up super fast, but even with the grids banging away the battery voltage went from 14.0 to 12.8V with the grids going off, and you don't even hear the change in the engine or the whine of the alternator, unlike with my old group27's

Anyways here is how you do it.

--------------------------------------------------------------------------------------------

Tools you will need.

1. A dremel or a drill with a drill bit.

2. A propane/ butane torch.

3. Battery Charger

4. Line wrenches for battery cables

---------------------------------------------------------------------------------------------

Procedure

1. You pull your old batteries out.

From here you will need a dremel, or a drill with a big drill bit. Either works good.

2. So first thing you need is to do is trim these notches off. If you don't the battery will not sit flat on the bottom of the tray, and this is crucial for the battery temp sensor to work correctly.

And the other side

3. Start by heating up the battery box sides with a torch. Take your time, as it is better to go slow and steady then race this step.

3A You want to torch from end to end.

3B So when you torch one side so it is nice and warm and pliable, you swap to the other side, and then before you drop the battery in you re-hit the first side again for another 30-45 seconds then drop her in.

To this end

4. Now torch away

5. Now after it is warm drop the battery in.

6. Let it cool down, and then pull it out. When your doing this you'll have to do this several times, its best to heat it up, and then drop it back in.

7. After each time you heat it up and drop the battery down you need to trim the plastic.

Here you can see the plastic where its getting bigger.

8. Now its important to keep doing this until the battery sits on the bottom of the tray.

This is the battery sensor, that my finger is on.

9. Hook up your batteries

9A. You may need to adjust the crossover cable between the two batteries in order to make the drivers side snug.

10. Use your 2/10/50 AMP battery charger to charge your batteries up. Once charged it works great.

Some additional notes.

1. I had to adjust the slack on the crossover battery cable so I could get the drivers side positive terminal to fit on snug.

2. The battery hold downs do fit just fine, if you get the battery all of the way to floor.

3. There is about an inch of clearance between the top of the batteries and the hood.

4. Its best to charge your batteries until they are fully full before starting the truck for the first time.

I'll update this with some videos in about a week when the weather turns.

**NOTE: Always look into upgrading your batteries and cables first!

If you have a mostly stock truck, you'll benefit from an alternator upgrade, but not as much as those that have big stereos, winches, camp trailers, excessive lighting, radio equipment etc... >>Good article<< I went through 3 "Lifetime Warranty" stock alternators from a big auto parts store before getting angry and spending the money.

If you put in a high output alternator and excessive draw without good cabling you can easily cause a fire. It's always recommended to have a fuse or circuit breaker on the charge line even though a few of these manufacturers say not to. Upgrading your battery cables in general helps in many areas. Google "Big 3 upgrade" for more information and no it does not just apply to stereos. The grounds are the most important.

A good battery with good capacitance usually helps more than an alternator, again these are for people with excessive demands who are unable to run their accessories without depleting the battery.

A lot of these alternators are plug and play with your PCM but some PCMs cant support them, so the manufacturers can build your alternator with separate regulator to bypass the PCM, its an option that usually has to be ordered. You may want to ask about the recommended option for your specific vehicle before purchase.

One other thing of mention, these alternators can be built in large cases or small cases. Small case alternators with really high outputs can generate excessive heat and as such reduce the effective output and life. This is why its not usually a good idea to have people "Re-wind" a stock alternator unless there's room in the case. Large case alternators will suffer the same the higher the output, so if you have 2 alternators with the same output with 2 different case sizes, get the bigger case so it can breathe! Some alternators require different size belts and are usually marked. There's also 6 phase alternators that provide a smoother power output due to more pickup points around the alternator. That's a whole different topic.

I made a tool to extract terminals from a VP44 connector.  It's just a bit of brass tubing.  I put it in a drill and sanded it down until it was small enough to fit into the front of the connector. 

You need to move the little red tabs.  This releases the lock that holds the terminals.   But it's not the only lock.

Insert the brass tube over the front of the terminal.  It should go in about 1/4" or so.  The tube will cover the barbs in the terminal... releasing the second lock.

Then pull out the terminal. 

.

Good times.

WARNING! Any time the batteries are disconnected, batteries ran dead, ECM disconnected, Accelerator Pedal Position Sensor (APPS Sensor) disconnected, Accelerator Pedal Position Sensor (APPS Sensor) replaced the Accelerator Pedal Position Sensor (APPS Sensor) calibration procedure MUST be done again to reset the Accelerator Pedal Position Sensor (APPS Sensor) idle and WOT limits. If the calibration is not done error codes and other issues must occur.

1. Disconnect the batteries and leave disconnected for at least 30 minutes. Now reconnect the batteries.

2. Turn key to ON position. (Do not Start)

3. Without starting engine, slowly press throttle pedal to floor and then slowly release. This step must be done (one time)>to ensure accelerator pedal position sensor calibration has been learned by ECM. If not done, possible DTC’s may be set.

4. Turn the key OFF.

NOTE: Disconnecting the batteries will not erase or reset error codes. All it does is erase the Accelerator Pedal Position Sensor (APPS Sensor) calibration in the ECM. As the video below will demostrate.

This right here is an IAT sensor for 98.5 to 02 Dodge Cummins 24V engine. This sensor has about 50k miles of gunk on it. This has ZERO impact on the sensor ability to read air temperature in the manifold. Cleaning the sensor will do nothing for performance or MPG. The way to check the IAT sensor for problems is with a live data tool like OBDLink, ScanGauge II or even the Quadzilla Adrenaline. Now at first key on of the day take note of the coolant and the IAT temperatures. The ECT and IAT temperatures should match. If they do match then nothing needs to be done as the IAT sensor is working correctly. If the ECT and IAT temperatures don't match then the IAT sensor will most likely need to be replaced. When doing this testing make sure the block heater is not plugged in for that night. 

(1998.5 - 2002 ISB)

ECU Hardware

There are 2 computers on the Ram. One on the passenger side firewall behind the air cleaner assembly (the Powertrain Control Module, or PCM), and the ECU, which is located on the left side of the engine, mounted directly on the engine block. The ECU is connected with a single 50-pin connector.

The ECU itself is a sealed unit, with a single air vent device. It is constructed of an aluminum 'frame', or center section, that has the mounting tabs to fasten it to the engine, and a sheet aluminum 'cover', that isn't really a cover at all - the flexible plastic 'circuit board' is adhered directly to the inside of this 'cover', on both sides. There is gray silicone sealer between the 'cover' and the 'frame'.

To open the ECU, one must remove the screws, and carefully pry the cover open. You must be sure to keep the cover straight and don't bend it, as the flexible circuit board is adhered directly to the inside of it. The side of the ECU with the electrical connector seems to contain power supply and other power-switching components (driver transistors, etc). I do not know if there are any ICs on this side, because I did not open mine up on that side (and at this point, I do not really want to). The other side contains the 'computer' components (processor, memory, etc) as shown below:



Most of the ICs inside are standard components. There are several unidentified components:

• 8L12A: 8-pin IC. Possibly 12V voltage regulator for flash programming?
• Phillips IC, marked '4651148 005633-- Fhr011B'. Maybe analog MUX for ADC inputs?
• Atmel IC, marled 'ENCORE 51R42722U02 82002253-001 A9D0013 9951'. I have no idea what this is for, it looks like an ASIC.
• 8-pin IC marked '74690 XAVS'
• 8-pin IC marked '3029009 1951130'. Near the filter choke. CAN bus driver?

The ECU only uses 256KB of flash, even if the installed chip is larger. The original ECU I opened had a 512KB chip (28F400). I later obtained another ECU, and discovered it had a 256KB chip (28F200). These flash chips are organized into a 16KB boot block, 2 8KB parameter blocks, and the remaining blocks are regular data blocks. The parameter blocks can sustain many more read/write cycles than the other blocks on the chip. There is 64k of RAM available, in the 2 32Kx8 SRAM chips.

The memory is organized as follows:

• 0x000000 - 0x3FFFFF: Flash. The first 16k (0x000000 - 0x004000) is the 'boot' part of the flash chip.
• 0x800000 - 0x80FFFF: RAM
• 0xFFD000 - 0xFFD7FF: Some unknown peripheral device. Perhaps the Atmel chip?
• 0xFFD800 - 0xFFDFFF: Intel CAN Controller
• 0xFFE000 - 0xFFEFFF: TPURAM (Refer to the MC68336 manual)
• 0xFFF000 - 0xFFFFFF: MC68336 internal functions/integrated peripherals

Software

Using a BDM interface cable and driver, I wrote a program that would dump the contents of the flash chip to a file for inspection. This was difficult because every so often during the data transfer, an error would occur. I solved this problem by only reading 2KB at a time. I later found out that this read error was occurring because of a 'watchdog timer' in the ECU hardware was attempting to assert RESET while I was reading the data (because when reading through the BDM port, the CPU is stopped). Once I modified the program to do 2KB reads I was able to get a successful read of the data. I used GNU objdump to create an assembler listing of the file. I have spent many hours 'picking apart' the program to figure out what each section is for, how the peripherals of the MC68336 are configured/used, etc.

There is a compressed program in the lower 16K (boot block) that gets decompressed into RAM at startup, only if certain conditions are met. This is probably a small program that is only good for reading the CAN bus, so that the flash can be reprogrammed. I have not spent much time examining this program.

The VIN of the vehicle is embedded in data around 0x4000, and again around 0x8000. There is also a 'signature' around 0x8000 that is checked at startup, and if it is valid, an address is read from location 0x800a and execution of the 'main' startup code continues at that address.

There is a considerable amount of data that gets moved from the end of the flash data into RAM at startup. In this example, the data begins at 0x3829e and ends at 0x3fee7. That is approx. 32KB of data.

At this time, I have only been able to identify the startup code, where the various components are initialized and addresses are set up, and parts of the program that read/write the CAN messages.

The following things need to be done:

• Identify the CAN messages themselves, the message contents, and what they mean.
• Identify which inputs connect to where (temp sensors, MAP, APPS, etc).
• Identify the other outputs and what ports they are located (Wait to start lamp, VP44 relay, fuel pump relay, intake heaters, etc.)
• Determine how the flash can be programmed by methods other than desoldering the chip from the board
• Identify the remaining program sections, and their assocaited data (the 'maps')

It would probably be useful to build a CAN interface for my PC, and 'watch' the data on the CAN bus while the engine is in operation. This might yield some information that can be used to identify more of the program.

Other information

It appears that the ECU itself was designed (and possibly manufactured) by Motorola. The ECU software, is unknown. There is no copyright message or any other identifying information in the dump of the flash memory, except the VIN number and the string '091197'. I do not know what language the program was originally written in, probably C, I really don't think something that large would be written in assembly language.

Why?

Because it is my truck, my ECU, my flash memory chip, etc. and I have a right to know how it works. And I also have the right to do what I want with it, whether that be drive it, or take the ECU out, sprinkle cheddar cheese on it and bake it in the oven, etc.

I think people should be able to understand, and repair if necessary, anything that they own, whether it be a computer, a car, a dishwasher, or a bike.

What's needed?

-Timbo Apps

- 10MM socket and wrench

- T20 torx

- Paperclip

- Mutlimeter

Timbo gave me a Timbo APPS sensor to install on my truck and try out. So I'll tell this much its built much better than the factory ~$450 dollar Dodge stock APPS sensor! I will say it works with the exhaust brake and is high idle ready with no compatibility issues. Timbo APPS sensor has no effect on these options and will continue to work as usual. What I love about the Timbo APPS is the fact there is no longer a need to for adjusting voltage for the APPS to function correctly or probing the PCM or ECM sockets.. And for you Timbo you need some serious Props for coming up with a simple fix for our tucks! My hats off to you sir!

But Here is my quick version write up of how to install a Timbo APPS sensor.

1. First you must remove the plastic cover over the bellcrank assembly. There is 2 plastic screws inside a expanding plug. You must remove the plastic screw without pushing against them. Kind of tricky but it can be done.

2. Then grab a 10mm socket and remove all 6 bolts holding the black plate to the mounting on the block...

3. Unplug the old APPS sensor.

4. Remove the 2 Torx screws holding the stock APPS sensor. This part I kind fudge over Timbo idea and made it simple. I grab a pair of pliers grab the head of the screw and broke them loose then used a T20 bit to finish removing. This way there is no worry about stripping the heads out.

5. Replace the APPS sensor with Timbo APPS sensor in the same position and line up the slot with the bellcrank tab. Use the supplied screw. Just before you finish tighten the screw turn the sensor fully clockwise to remove extra twisting slack. (As seen in this picture)

6.Plug in the wiring and re-assemble the APPS sensor plate again with the 6 bolts.

7. Now adjust for slack. Use the supplied paper clip and insert it in the green port on the plug. Turn your key ON and look at the voltage. Now using the screw on the bellcrank stop (one towards the front) adjust till the voltage rises the back off till you hit your original mark plus 1/2 turn. Since mine was .633 I turn till it rose and the backed off to .633 and then another 1/2 turn. Your all set!

WARNING! Don't try to adjust the voltage to the voltage on the tag of the old sensor. This is not required nor should be done. Timbo's APPS has no voltage to set to. Also don't bother to try and probe at the PCM this is not required ether!

Take notice the final voltage on the DMV (Digital Volt Meter) is no where near the voltage listed on the old stock APPS.

8. Disconnect your batteries and do a APPS Reset.

Mopar's Notes: Anyway's, just thought you could put a comment at the bottom of your Timbo APPS write up to tell people that the voltage/set screw adjustment isn't REQUIRED but certainly nice to do to avoid a dead spot at the top of the pedal movement. - Derrick Lucas

Solder them together like this: 

I pulled the bezel off and pulled the headlight switch right out because of my OCD, and if I can recall correctly (didn't tear my dash apart to check), I tapped the 'park lamp replay output' black w/ yellow tracer wire for the park light power source, as seen on the headlight switch connector here:

You may be able to trace the wire down near the steering column area for easier access, but I thought it was pretty well buried, which I why I went up the dash to the headlight switch. 

Lastly, the right and left turn signal wires are very easy to get at, right on the steering column. They are the small, tan and light-green wires respectively, just be sure to check everything beforehand with a multimeter. 

The original idea was from a gentleman, can't remember his name or find the thread, on the CF who did this to his 3rd? gen ~ credit goes to him.