Hi, I have a 2001 dodge 3500

Cummins diesel.I have a dead fuel gauge issue that doesn't seem quite like the others that I have researched,so I could use some help. It reads empty at all times, UNLESS I unplug the batteries for 15-20 minutes and let the truck reset. At this time the fuel gauge will read full for about 15 mins, before it slowly drops to empty again and stays there permenantly. Here is what I have done. I have dropped the tank and I have replaced the entire canister/float/fuel level sending unit. I used an volt meter on the new sending unit and as I moved the float up and down I watched the resistance change. I have done the gauge test and watched the gauge move through its full range of motion. I have also looked at the wiring harness underneath the front driver wheel well where the wires are exposed before they enter the harness, and the wires above the fuel tank to look for any breaks in the connection. I have a fass fuel pump and fuel pressure gauge and everthing reads normal as far as that is concerned.  Any ideas? Thanks for your time. 

Here is the full article on it...

 

Ok guys, newest development. My overhead display quit giving me a " distance till empty" reading, it's just says "SC" now. I've still got mileage and odometer and the rest of the stuff but not that. That reveal anything new?

Is the odometer still clocking distance?

Yes sir

Okay, when things go like this I have to try things on the list that's in square one/ back to basics.

 

Batteries have good clean connections

Low AC voltage emanating from the alternator when running

PCM grounding good clean to firewall

Pass battery to PCM ground good clean and tight. check the factory clip connection laying around the wheel well.

Take apart ground connections and look for corrosion.

Alternator grounding well thru its mounting bracket to engine block

ECM well grounded to block

Take off the ground to the engine block, the heavy cable going down below, and clean the lug and mate surface Theer might be two of them on the 24 valves.

 

  On 7/25/2016 at 3:08 AM, Mopar1973Man said:

 

Chrysler Crash Detection

 

This isn't like vehicle crash but data crash. It's built on the same design as ethernet cable networks. 

I had the CCD come on a while back, I lost all gauges. it ended being a loose connection on the main plug on the PCM. got it snugged down and problem went a way. It was also throwing a code, I forgot what number but it related to a bad transmission circuit, between that and the CCD, I was really

Ok jag I'll start knocking things off that list, and I'll check the main pcm plug also. I unplugged the three connections at the the pcm and cleaned them, and I cleaned the harness under the wheel well, all looked clean anyhow but I did them anyway.

Weird one to check...

 

WARNING! - Please be careful with the bolt holding this plug it extremely easy to strip out. 

 

The big plug in the PDC box has the CCD bus in that plug I wonder if the connection is poor or loose and creating issues. 

  On 7/26/2016 at 2:39 AM, Mopar1973Man said:

Weird one to check...

 

WARNING! - Please be careful with the bolt holding this plug it extremely easy to strip out. 

 

The big plug in the PDC box has the CCD bus in that plug I wonder if the connection is poor or loose and creating issues. 

Yep, that's the one I meant PDC box, not pcm, the big black/white one with bolt in center. And found out  thier is a fine line between snug and stripped

  On 7/26/2016 at 2:54 AM, 01cummins4ever said:

And found out  thier is a fine line between snug and stripped

 

Crap another one. 

My 2 Cents.
The PCM continually monitors the fuel tank sending unit, then sends the proper messages to the
instrument cluster thru Chrysler Collision Detection (CCD) data bus.

 

Message Failure - If the cluster fails to receive
a percent tank full message, it will hold the gauge
needle at the last indication until a new message is
received, or until the ignition switch is turned to the
Off position, whichever occurs first.

 

// (CCD) data ID 37 Fuel Level Sensor.
// Tested on 2000 Dodge Durango PCM, 20 ohms - full <-> 240 ohms - empty

 

// Fuel ID 37~[HEX-25] (ID-DATA-CRC)
// DATA range 1 ~ 253 + Error handling, P0461, P0462 and P0463 are all related to the fuel level sending unit.

// If DATA equals 255: Error open-circuit, P0463 Fuel Level Sensor Circuit High Input  
// If DATA equals 254: Range/performance, P0461 Fuel level sensor circuit range/performance.
// When is the code P0461 detected?
// The output signal of the fuel level sensor does not change within the specified range even though the vehicle has been driven a long distance.

// If DATA equals 0: Error short-circuit, P0462 Fuel Level Sensor Circuit Low Input.

 

// P0463 Fuel Level Sensor Circuit High Input
// @ 1Kohms to ∞ infinite resistance Ohms, (DATA equals 255) = Error open-circuit 
// DEC: 37 255 36
// HEX: 25 FF 24

 

// P0461 Fuel level sensor circuit range/performance
// DEC: 37 254 35
// HEX: 25 FE 23

 

// P0462 Fuel Level Sensor Circuit Low Input
// @ 10 to 0 Ohms (DATA equals 0), Error short-circuit
// DEC: 37 0 37
// HEX: 25 0 25

 

// @ 240 Ohm empty.
// DEC: 37 1 38
// HEX: 25 1 26

 

// @ 220 Ohm nearly empty.
// DEC: 37 8 45
// HEX: 25 8 2D

 

// @ 180 ohm, before the low fuel light.
// DEC: 37 54 91
// HEX: 25 36 5B

 

// @ 179 Ohm, Fuel Reserve Light on (Data 53 to 1)
// DEC: 37 53 90
// HEX: 25 35 5A

 

// @ 20 ohm full
// DEC: 37 253 34
// HEX: 25 FD 22

That last post was probably extremely helpful, but not for my pea brain?.

Btw, tightening down the connector in the PDC seems to have removed the "ccd" error, I had it come on everyday for the past week multiple times and for 10 mins at a time. After tightening down that connector I have driven to straight days and haven't seen that error. So kudos for that suggestion!??

@Atcmcc Did the gauge start tot function? 

 

@Chris O. Could you provide me information for PCM header address and the PID for said fuel gauge information? Plz! I want to add it to the OBDLink App.

Mike,

 

I dont think the obd stuff will work,  you will need a CCD bus chip rather the obd stuff.   I think it is on a different protocol and buadrate.

Edited July 27, 20168 yr by Me78569

  On 7/27/2016 at 6:01 PM, Atcmcc said:

That last post was probably extremely helpful, but not for my pea brain?.

Btw, tightening down the connector in the PDC seems to have removed the "ccd" error, I had it come on everyday for the past week multiple times and for 10 mins at a time. After tightening down that connector I have driven to straight days and haven't seen that error. So kudos for that suggestion!??

So does the fuel gauge work properly now?

 

  On 7/27/2016 at 8:49 PM, Me78569 said:

Mike,

 

I dont think the obd stuff will work,  you will need a CCD bus chip rather the obd stuff.   I think it is on a different protocol and buadrate.

That is correct.

The CCD bus protocol level is different, no public information is available.
You have to disassembling reverse engineering to find out how things work.  

Nope, gauge is still dead  but the ccd on the overhead went away. Still no "dte" either. Im still making my way through jags list of suggestions on the grounds and plugs, knocked a few of them out today at lunch.

Thanks for the vote of confidence in my list. I'm a light weight electrical guy.

 

Have you found any corrosion or tainted connections?

 

The alternator grounds thru the mounting bracket. Being that it is painted I got the volt meter out and set it to OHMS and checked for resistance from alt housing to a clean unpainted surface on the engine. I found a noticeable degree of resistance on the meter. I was surprised as my engine is very clean and still looks new with only 85k miles.

 

After doing some reading about the importance in have a good alt ground helping to reduce AC noise and a general betterment of the DC system I installed a no. 8 wire and small lug terminal attached to an alternator housing bolt and back to the passenger battery ground. I don't know if it has helped but I know its a better ground and better protection for the more sensitive electronic circuits aboard. At least the batteries can do a better job of absorbing harmful AC noise.

 

Another thing I've noticed is I don't have any white powder corrosion on the battery terminals any longer, which used to be aggressive.

 

I wish I could be more helpful anyway.

Edited July 28, 20168 yr by JAG1

Only one corroded ground so far, ( driver battery ground) my truck only has 83,000 on it now, it's the cleanest 2nd gen I've seen, especially living out here in md where everything is rusted to hell! 

You and me are about the same miles  mines clean too.

 

Have you checked the alternator ground bracket for resistance? I good ground there helps reduce PCM confusion from AC noise..

Edited July 29, 20168 yr by JAG1

Here is your master ground for the computers.

As for cab grounds they are in the driver side kick panel. There is a second connection in the center of the dash too. You'll most likely have to either pull the dash to see or lay on your back and use a mirror. Still in all that ground goes to the kick panel in the end and typically most problems are at the kick panel from rusting.