Mopar1973Man

CYLINDER COMPRESSION/LEAKAGE TESTS CYLINDER COMPRESSION PRESSURE The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions. Ensure batteries are completely charged and the engine starter motor is in good operating condition. Otherwise, the indicated compression pressures may not be valid for diagnostic purposes. 1. Disconnect the fuel inlet line to the fuel filter housing. Plug the fuel line from the fuel tank. NOTE: Failure to plug fuel line will result in fuel leak. 2. Remove fuel transfer pump relay from PDC. 3. Start the engine and idle until the engine stalls (runs out of fuel). 4. Remove the cylinder head cover. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL) 5. Remove the cylinder head cover carrier gasket. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL} 6. Remove the high pressure fuel line between the cylinder head and fuel rail for the cylinder to be tested. Use tool 9864 to cap this fuel rail on the cylinder being tested. 7. Remove the fuel connector tube nut and fuel connector tube. 8. Remove the exhaust rocker lever. 9. Use Tool 9010 to remove the injector and copper sealing washer. 10. Install the exhaust rocker lever and torque to 36 N·m (27 ft. Ibs.). 11. Cover the remaining rocker levers with clean shop towels to prevent any oil splatter under the hood. 12. Place a rag over the compression test tool fitting. Crank the engine for 2-3 seconds to purge any fuel that may have drained into the cylinder when the injector was removed. 13. Connect the compression test gauge. 14. Crank the engine for 5 seconds and record the pressure reading. Repeat this step three times and calculate the average of the three readings. NOTE: The minimum cylinder pressure is 350 psi. Cylinder pressure should be within 20% from cylinder to cylinder. 15. Combustion pressure leakage can be checked if cylinder pressure is below the specification. Perform the leakage test procedure on each cylinder according to the tester manufacturer instructions. 16. Upon completion of the test check and erase any engine related fault codes. CYLINDER COMBUSTION PRESSURE LEAKAGE The combustion pressure leakage test provides an accurate means for determining engine condition. Combustion pressure leakage testing will detect: • Exhaust and intake valve leaks (improper seating). • Leaks between adjacent cylinders or into water jacket. • Any causes for combustion/compression pressure loss 1. Start and operate the engine until it attains normal operating temperature. 2. Disconnect injector harness connectors. 3. Disconnect CCV tube and breather drain tube from valve cover. 4.Remove the cylinder head cover. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL) 5.Disconnect harness from injectors. 6.Remove the cylinder head cover carrier gasket. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL) 7. Bring the cylinder to be tested to TDC. 8. Remove the high pressure fuel line between the cylinder head and the fuel rail for the cylinder to be tested. 9. Install capping Tool 9864 onto the rail. 10. Remove the high pressure connector nut and high pressure connector with Tool 9015. 11. Remove the exhaust and intake rocker lever. 12. Use Tool # 9010 to remove the injector and copper sealing washer. 13. Install compression test Tool # 9007 into the' injector bore. 14. Connect the leakage tester and perform the leakage test procedure on each cylinder according to the tester manufacturer's instructions. 15. Upon completion of the test check and erase any engine related fault codes.

CAN BUS COMMUNICATION DESCRIPTION The primary onboard communication network between microprocessor~based electronic control modules in this vehicle is the Controller Area Network (CAN) data bus system. A data bus network minimizes redundant wiring connections; and, at the same time, reduces wire harness complexity, sensor current loads, and controller hardware by allowing each senSing device to be connected to only one module (also referred to as a node). Each node reads then broadcasts its sensor data over the bus for use by other nodes requiring that data. Each node ignores the messages on the bus that it cannot use. The CAN bus is a two-wire multiplex system. Multiplexing is any system that enables the transmission of multiple messages over a single channel or circuit. The CAN bus is used for communication between most vehicle nodes. However, in addition to the CAN bus network, certain nodes may also be equipped with a dedicated Serial Controller Interlace (SCI) or a K-Line serial link bus to provide direct communication between that node and certain sensor inputs. There are actually three separate CAN bus systems used in the vehicle. They are designated: the CAN-B, the CAN-C and the Diagnostic CAN-C. The CAN-B and CAN-C systems provide on-board communication between all nodes in the vehicle. The CAN-C is the faster of the two systems providing near real-time communication (500 Kbps), but is less fault tolerant than the CAN-B system. The CAN-C is used typically for communications between more critical nodes, while the slower (83.3 Kbps), but more fault tolerant CAN-B system is used for communications between less critical nodes. The CAN-8 fault tolerance comes from its ability to revert to a single wire communication mode if there is a problem in the bus wiring. The added speed of the CAN data bus is many times faster than previous data bus systems. This added speed facilitates the addition of more electronic control modules or nodes and the incorporation of many new electrical and electronic features in the vehicle. The Diagnostic CAN-C bus is also capable of 500 Kbps communication. and is sometimes informally referred to as the CAN-D system to differentiate it from the other high-speed CAN-C bus. The Diagnostic CAN-C is used exclusively for the transmission of diagnostic information between the Totally Integrated Power Module/Central GateWay (TJPM or TIPMCGW) and a diagnostic scan tool connected to the industry-standard 1 B-way Data Link Connector (DLC) located beneath the instrument panel on the driver-side of the vehicle. The TIPM is located in the engine compartment near the battery. The central CAN gateway or hub module integral to the TIPMs connected to all three CAN buses. This gateway physically and electrically isolates the CAN buses from each other and coordinates the b;-directional transfer of messages between them. OPERATION The Controller Area Network (CAN) data bus allows aU electronic modules or nodes connected to the bus to share information with each other. Regardless of whether a message originates from a module on the lower speed CAN-B bus or on the higher speed CAN-C or CAN·D bus, the message structure and layout is similar, which allows the Totally Integrated Power Module/Central GateWay (TIPM or TIPMCGW) to process and transfer messages between the buses. The TIPM also stores a Diagnostic Trouble Code (DTC) for certain bus network faults. All modules (also referred to as nodes) transmit and receive messages over one of these buses. Data exchange between nodes is achieved by serial transmission of encoded data messages. Each node can both send and receive serial data simultaneously. Each digital bit of a CAN bus message is carried over the bus as a voltage differential between the two bus circuits whiCh, when strung together, form a message. Each node uses arbitration to sort the message priority jf two competing messages are attempting to be broadcast at the same time. The voltage network used to transmit messages requires biasing and termination. Each module on the CAN bus network provides its own biaSing and termination. There are two types of nodes used in the CAN bus net.w0rk. On the CAN-C bus, a dominant node has a 120-ohm termination resistance, white a non-dominant (or recessive) node has about a 2500 to 3000 ohm (2.5 to 3.0 kilohm) termination resistance. The dominant nodes on the CAN·C bus are the TIPM and the Powertrain Control Module (PCM). The termination resistance of two dominant nodes is combined in parallel to provide a total of about 60 ohms. This resistance value may vary somewhat by application, depending upon the number of non-dominant nodes on the CAN-C bus. On the CAN-D bus (or Diagnostic CAN-C) an of the 60-ohm termination resistance is present in the Central GateWay (TIPMCGW). NOTE: Termination resistance of a CAN-B node cannot be verified with a Digital Multi-Meter (DMM) or Digital Volt Ohm Meter (DVOM). The transceiver of each CAN-B node connects to termination resistors internally. When the vehicle battery Is disconnected, the internal connections of all CAN Bus node transceivers are switched open, disconnecting the termination resistors. Therefore, the total bus resistance measured under these conditions will be extremely high or infinite, which does not accurately reflect the actual termination resistance of the CAN-B bus. The communication protocol is used for the CAN data bus is a non-proprietary, open standard adopted from the Bosch CAN Specification 2.0b. The CAN-C is the faster of the two primary buses in the CAN bus system, providing near real-time communication (500 Kbps). The CAN bus nodes are Connected in parallel to the two-wire bus using a twisted pair, where the wires are wrapped around each other to provide shielding from unwanted electromagnetic induction, thus preventing interference with the relatively low voltage signals being carried through them. The twisted pairs have between 33 and 50 twists per meter (yard). While the CAN bus is operating (active), one of the bus wires will carry a higher voltage and is referred to as the CAN High or CAN bus (+) wire, while the other bus wire will carry a lower voltage and is referred to as the CAN Low or CAN bus (-) wire. Refer to the CAN Bus Voltages table.

CP3 INJECTION PUMP DESCRIPTION A Robert Bosch high-pressure CP3 fuel injection pump is used. The CP3 pump is attached to the back at the timing gear housing at the left ftront side of the engine. OPERATION The CP3 fuel injection pump supplies high pressure to the fuel rail independent of engine speed. This high pressure is then accumulated in the fuel rail. High-pressure fuel is constantly supplied to the injectors by the fuel rail. The Engine Control Module (ECM) controls the fueling and timing of the engine by actuating the injectors. Fuel enters the system from the electric fuel transfer (lift) pump, which is located in the fuel tank. Fuel is forced through the fuel filter element and then enters the Fuel Pump/Gear Pump. which is attached to the rear of the CP3 fuel injection pump. The Fuel Pump/Gear Pump is a low-pressure pump and produces a minimum pressure of 440 kpa (64psi). Fuel then enters the CP3 fuel injection pump. Low-pressure fuel is then supplied to the FCA (Fuel Control Actuator). The FCA is an electronically controlled solenoid valve. The ECM controls the amount of fuel that enters the high-pressure pumping chambers by opening and closing the FCA based on a demanded fuel pressure. The FPS (Fuel Pressure Sensor) on the fuel rail provides the actual fuel pressure. When the actuator is opened, the maximum amount of fuel is being supplied to the CP3 fuel injection pump. Any fuel that does not enter the injection pump is directed to the cascade overflow valve. The cascade overflow valve regulates how much excess fuel is used for lubrication of the pump and how much is returned to the tank through the drain manifold. Fuel entering the injection pump is pressurized to between 200-1800 bar (2901 - 26107 psi) by three radial pumping chambers. The pressurized fuel is then supplied to the fuel rail. REMOVAL CAUTION: Cleanliness cannot be overemphasized when handling or replacing diesel fuel system components. This especially includes the fuel injectors, high-pressure fuel lines and CP3 fuel injection pump. Very tight tolerances are used with these parts. Dirt contamination could cause rapid part wear and possible plugging of fuel injector nozzle tip holes. This, in turn, could lead to a possible engine misfire. Always wash/clean any fuel system component thoroughly before disassembly and then air dry. Cap or cover any open part after disassembly. Before assembly, examine each part for dirt, grease or other contaminants and clean if necessary. When installing new parts, lubricate them with clean engine oil or clean diesel fuel only. 1. Disconnect both negative battery cables at both batteries. Cover and isolate ends of both cables. 2. Remove intake manifold air intake tube (above injection pump) and its rubber connector hose. 3. Remove accessory drive belt. 4. Thoroughly clean rear of injection pump, and attachment points for its fuel lines. Also clean the opposite ends of these same lines at their attachment points. 5. Disconnect quick-connect fitting by pressing on button. CAUTION: Whenever a fuel line fitting is connected to. a secondary fitting, always use a backup wrench on the secondary fitting. Do not allow the secondary fitting to rotate. 6. Remove high-pressure fuel line to fuel rail. 7. Remove banjo bolt. 8. Disconnect FCA (Fuel Control Actuator) electrical connector. 9. Remove line clamp. 10. Remove fuel pump drive gear access cover with a 3/8" drive ratchet. Access cover is threaded to timing gear cover. 11. Remove fuel pump drive gear mounting nut and washer. 12. Attach C3428B, or L4407A (or equivalent) gear puller to pump drive gear with 2 bolts, and separate gear from pump (a keyway is not used on this particular injection pump). Leave drive gear hanging loose within timing gear cover. 13. Remove three injection pump mounting nuts (6), and remove pump from engine. INSTALLATION 1. Inspect pump mounting surfaces at pump and mounting flange and pilot bore for nicks, cuts or damage. Inspect O-ring surfaces for nicks, cuts or damage. 2. Clean injection pump mounting flange and pilot bore at gear housing. Also clean front of injection pump. 3. Install new rubber O-ring (square) into machined groove at pump mounting area. 4. Apply clean engine oil to injection pump O-ring and pilot bore only. The machined tapers on both injection pump shaft and injection pump gear must be absolutely dry, clean and free of any dirt or oil film. This will ensure proper gear-to-shaft tightening. 5. Clean pump gear and pump shaft at machined tapers with an evaporative type cleaner such as brake cleaner. 6. FUEL INJECTION PUMP PHASING: Perform the following phasing procedure anytime the injection pump has been removed and re-installed. 7. Locate the end of the fuel injection pump shaft. Two numbers (750 and 0) are stamped into the end of the shaft. 8. Rotate the injection pump shaft until the number 5 (located in the center of number 750) is positioned at 9 o'clock. 9. Position injection pump to mounting flange on gear housing while aligning injection pump shaft through back of injection pump gear. Be sure the number 5 is still at the 9 o'clock position. 10. Bring the engine to TOe position. Do this by rotating the crankshaft until the TDe mark on the crankshaft damper is at 12 o'clock position. It does not matter if cylinder #1 or #6 is at top. Again, check to be sure the number 5 is still at the 9 o'clock position. Rotate pump shaft accordingly. 11. After pump is positioned flat to mounting flange, install three pump mounting nuts and tighten finger tight only. Do not attempt a final tightening at this time. Do not attempt to tighten (pull) pump to gear housing using mounting nuts. Damage to pump or gear housing may occur. The pump must be positioned flat to its mounting flange before attempting to tighten three mounting nuts. 12. To prevent damage or cracking of components. install and tighten nuts in the following sequence: a. Install injection pump shaft washer and nut to pump shaft. Tighten nut finger tight only b. Do preliminary (light) tightening of injection pump shaft nut (1). c. Tighten three injection pump mounting nuts to 24 N·m (18 ft. Ibs.). d. Do a final tightening of pump shaft nut to 105 N·m (77 ft. Ibs.). 13. Install drive gear access cover using a 3/8" drive ratchet. Access cover is threaded to timing gear cover. Tighten to 8 N·m (71 in. Ibs.) torque. 14. Install fuel return line. Tighten banjo bolt to 24 N·m (18 ft. Ibs.) torque. 15. Install quick-connect fitting. 16. Install fuel line (injection pump-to-fuel rail). Using a back up wrench, tighten fitting at fuel pump to 40 N·m (30 ft. Ibs.) torque. Tighten fitting at fuel rail to 40 N·m (30 ft. Ibs.) torque. 17. Install clamp. 18. Connect Fuel Control Actuator (FCA) electrical connector to rear of injection pump. 19. Install rubber intake manifold air intake tube. Tighten clamps . 20. Install accessory drive belt. 21. Connect both negative battery cables to both batteries. 22. Check system for fuel or engine oil leaks.

FUEL HEATER OPERATION The fuel heater is used to prevent diesel fuel from waxing during cold weather operation. When the fuel temperature is below 45° ±8 F (7°C), the temperature sensor allows current to flow to the heater element warming the fuel. When the fuel temperature is above 75 0 ±8 F (24°C), the sensor stops current flow to the heater element. Battery voltage to operate the fuel heater element is supplied from the ignition switch and through a solid stated device in the TIPM. The fuel heater element and "solid state device in TIPM" are not computer controlled.The heater element operates on 12 volts, 300 watts at 0° F (-18° C). DIAGNOSIS AND TESTING FUEL HEATER The fuel heater is used to prevent diesel fuel from waxing during cold weather operation. NOTE: The fuel heater element, "solid state device in TIPM" is not controlled by the Engine Control Module (ECM). A malfunctioning fuel heater can cause a wax build-up in the fuel filter/water separator. Wax build-up in the filter/separator can cause engine starting problems and prevent the engine from revving up. It can also cause blue or white fog-like exhaust. If the heater is not operating in cold temperatures, the engine may not operate due to fuel waxing. The fuel heater assembly is located on the side of the fuel filter housing and internal to the fuel filter housing. The heater assembly is equipped with a built-in fuel temperature sensor (thermostat) that senses fuel temperature. When fuel temperature drops below 45° ± 8° F (7° C), the sensor allows current to flow to the built-in heater element to warm fuel. When fuel temperature rises above 75 o± 8° F (24° C), the sensor stops current flow to heater element ( the circuit is open). Voltage to operate fuel heater element is supplied from the ignition switch, though solid state device in TIPM, to fuel temperature sensor and on to fuel heater element. The heater element operates on 12 volts, 300 watts at 0 OF (-18° C). As temperature increases, power requirements decrease. A minimum of 7 volts is required to operate the fuel heater. The resistance value of the heater element is less than 1 ohm (cold) and up to 1000 ohms warm. TESTING 1. Disconnect the electrical connector from the heater element. Ambient temperature must be below the circuit close temperature. If necessary, induce this ambient temperature by placing ice packs on a thermostat to produce an effective ambient temperature below circuit close temperature. Measure resistance across two pins. Operating range is 0.3 - 0.45 Ohms. 2. If resistance is out of range, replace heater element.

FUEL SYSTEM PRIMING A certain amount of air becomes trapped in the fuel system when fuel system components on the supply and/or high-pressure side are serviced or replaced. Fuel system priming is accomplished using the electric fuel transfer (lift) pump. Servicing or replacing fuel system components will not require fuel system priming. The fuel transfer (lift) pump is self-priming: When the key is first turned on (without cranking engine), the pump operates for approximately 1 to 2 second and then shuts off (Note: When ambient temperatures are cold enough to cause the intake air heaters to operate, the fuel lift pump will operate during the entire intake air pre-heat cycle). The pump will also operate for up to 25 seconds after the starter is quickly engaged, and then disengaged without allowing the engine to start. The pump shuts off immediately if the key is on and the engine stops running. 1. Turn the key to CRANK position and quickly release the key to ON position before engine starts. This will operate fuel transfer pump for approximately 25 seconds. 2. Crank engine. If the engine does not start after 25 seconds, turn the key to OFF position, and leave it off for at least 5 seconds. Repeat the previous step until the engine starts. 3. Fuel system priming is now completed. 4. Attempt to start the engine. If the engine will not start, proceed to following steps. When the engine does start, it may run erratically and be noisy for a few minutes. This is a normal condition. CAUTION: Do not engage the starter motor for more than 30 seconds at a time. Allow two minutes between cranking intervals. 5. Perform previous fuel priming procedure steps using fuel transfer pump. Be sure fuel is present at the fuel tank. 6. Crank the engine for 30 seconds at a time to allow fuel system to prime. WARNING: The fuel injection pump supplies extremely high fuel pressure to each individual injector through the high-pressure lines. Fuel under this amount of pressure can penetrate the skin and cause personal injury. Wear safety goggles and adequate protective clothing. Do not loosen fuel fittings while the engine is running.

GRID HEATER RELAY OPERATION The Engine Control Module (ECM) operates the heating element through the intake manifold air heater relay. Refer to the Diagnostic Procedures section for an electrical operation and complete description of the intake heater, including pre-heat and post-heat cycles. REMOVAL The intake manifold air heater relay (5) is located in the engine compartment. It attached to a bracket. This bracket is attached to the right battery tray (3). The mounting bracket and relay is replaced as an assembly. 1. Disconnect both negative battery cables at both batteries. 2. Disconnect relay trigger wires (4) at relays. Note position of wiring before removing. 3. Remove nuts (2) at cable connectors and disconnect cables (1) from mounting studs. Note position of cables before removing. 4. Remove two relay mounting bracket screws (6) and remove relay assembly. INSTALLATION The intake manifold air heater relay (5) is located in the engine compartment. It attached to a bracket. This bracket is attached to the right battery tray (3). The mounting bracket and relay is replaced as an assembly. 1. Position relay and install two relay mounting bracket screws (6). 2. Position cables (1) to mounting studs and install nuts (2). 3. Connect relay trigger wires (4) at relays. 4. Connect both negative battery cables to both batteries.

Grid Heater Light On While Driving If you happen to notice your grid heater light is on while your driving this is a sign of injector failure. The ECM has the ability to detect excessive return flow from the injectors. Grid heater light is a warning to the owner that the injectors are worn out and all six injectors should be replaced very soon.

INTAKE GRID HEATER OPERATION The air heater element is used to heat incoming air to the intake manifold. This is done to help engine starting and improve driveability with cool or cold outside temperatures. Electrical supply for the air heater element is controlled by the Engine Control Module (ECM) through the air heater relay. Refer to Intake Manifold Air Heater Relay for more information. A heavy-duty cable connects the air heater element to the air heater relay. This cable will supply 12-volts to an individual' heating element within the heater block assembly. The following chart displays the pre-heat, or turn-on times (in seconds) of the wait-to-start lamp. If the intake manifold temperature is above 66.09 degrees Fahrenheit, the wait-to-start lamp will not illuminate. Consequently, the intake air heater element will not be activated. WAIT-TO-START LAMP TURN ON TIMES REMOVAL If servicing the heater element, the entire block/element assembly (integrated intake cover) must be replaced. 1. Disconnect both negative battery cables at both batteries. Cover and isolate ends of both cables. 2. Remove both the intake manifold air intake tube (above injection pump), and its rubber connector hose. 3. Remove fuel rail and high-pressure fuel lines. Refer to Fuel Rail Removal. 4. Loosen clamp securing EGR crossover tube to EGR valve. Also, loosen opposite end of EGR crossover tube. Remove clamp from intake connection. 5. Remove air intake connection mounting bolts. 6. Remove air intake connection. 7. Remove heater cable nut and disconnect heater cable from stud. 8. Disconnect electrical connectors. 9. Disconnect crankcase vent line at top of valve cover. 10. Disconnect crankcase pressure sensor electrical connector. 11. Disconnect engine oil dipstick tube bracket. 12. Remove mounting bolts and remove heater element assembly. 13. Remove and discard gasket. INSTALLATION 1. Clean top of intake manifold and bottom of heater assembly. 2. Install new gasket. 3. Position assembly to top of manifold. 4. In~tall mounting bolts. TIghten to 24 N·m (18 ft. Ibs.). 5. Attach engine oil dipstick t~be bracket. 6. Install fuel rail and all high-pressure fuel lines. Refer to Fuel Rail Installation. 7. Position air intake connection. 8. Install air intake connection mounting bolts. TIghten bolts to 24 N·m (18 ft. Ibs.). 9. Install new EGR crossover tube gaskets to crossover tube. 10. lighten crossover tube clamps. 11. Connect heater cable to stud. 12. Install heater cable nut. 13. Connect electrical connectors. 14. Connect crankcase vent line at top of valve cover. 15. Connect crankcase pressure sensor electrical connector. 16. Connect rubber connector hose (2) and intake tube to air intake housing. Tighten clamp bolts to 11 N·m (100 in. Ibs.) torque. 17. Connect both negative battery cables at both batteries.

INTAKE TEMPERATURE & PRESSURE SENSOR OPERATION The Inlet Air Temperature/Pressure Sensor is a combination dual-function sensor. The sensor element extends into the intake air stream at the top of the air filter housing. Ambient air temperature, as well as barometric pressure, is monitored by this sensor. The Engine Control Module (ECM) monitors signals from this sensor. REMOVAL The Inlet Air Temperature/Pressure Sensor (3) is located on the air cleaner cover. 1. Disconnect electrical connector (7) at sensor. 2. Remove mounting screw (2). 3. Remove sensor from air cleaner cover. 4. Check condition of sensor a-ring. INSTALLATION 1. Check condition of sensor a-ring. 2. Position sensor (3) into top of air cleaner cover with a slight twisting action. 3. Install mounting screw (2). 4. Install electrical connector (7).

MASS AIR FLOW SENSOR (MAF) OPERATION The Mass Airflow (MAF) sensor is a frequency based device. A constant voltage is applied to a heated wire on the sensor. This wire is positioned in the air cleaner air stream and is heated by the electrical current that the voltage produces. As air flows across it, it cools down. The heated wire or film is a positive temperature coefficient resistor. This means that its resistance drops when its temperature drops. The drop in resistance allows more current to flow through it in order to maintain the programmed temperature. This current is changed to a frequency which is sent to the Engine Control Module (ECM) and interpreted as air flow. Adjustments for air temperature and humidity are taken into consideration because they also affect the temperature of the heated wire or film. REMOVAL The Mass Airflow Sensor (5) is located on the air cleaner cover (8). 1. Disconnect electrical connector (6) at sensor. 2. Remove two mounting screws (4). 3. Remove sensor from air cleaner cover. INSTALLATION 1. Check condition of sensor O-ring. 2. Position sensor into top of air cleaner cover with a slight twisting action. 3. Install mounting screw (4). 4. Install electrical connector (6).

IAT TEMPERATURE & MAP PRESSURE SENSOR OPERATION The combination, dual function Intake Manifold Air Temperature Sensor/MAP Sensor is installed into the top of the intake manifold with the sensor element extending into the air stream. The IAT portion of the sensor provides an input voltage to the Engine Control Module (ECM) indicating intake manifold air temperature. The MAP portion of the sensor provides an input voltage to the ECM indicating turbocharger boost pressure. REMOVAL The combination, dual function Intake Manifold Air Temperature Sensor/MAP (IAT/MAP) (3) sensor is installed into the intake air connection manifold, -below, and to the rear of the EGR valve (5). 1. Clean area around sensor. 2. Disconnect electrical connector (2) from IAT/MAP sensor. 3. Remove mounting screw (4). 4. Remove sensor from manifold. 5. Check condition of sensor O-ring. INSTALLATION The combination, dual function Intake Manifold Air Temperature Sensor/MAP (lAT/MAP) (3) sensor is installed into the intake air connection manifold, below, and to the rear of the EGR valve (5). 1. Check condition of sensor a-ring. 2. Clean sensor mounting area at intake manifold. 3. Lubricate sensor O·ring and sensor mounting hole in intake manifold with clean engine oil. 4. Position sensor (3) into intake manifold. 5. Install and tighten sensor mounting screw (4) to 1 N·m (9 in. Ibs.) torque. .6. Connect electrical connector (2) to sensor.

FUEL CONTROL ACTUATOR DESCRIPTION The Fuel Control Actuator (FCA) (3) is located at the rear of the high-pressure, fuel injection pump. OPERATION The Fuel Control Actuator (FCA) is an electronically controlled solenoid valve. The ECM controls the amount of fuel that enters the high-pressure pumping chambers by opening and closing the FCA based on a demanded fuel pressure. When the FCA is opened, the maximum amount of fuel is being supplied to the fuel injection pump. Any fuel that does not enter the injection pump is directed to the cascade overflow valve. The cascade overflow valve regulates how much excess fuel is used for lubrication of the pump and how much is returned to the fuel tank through the drain manifold. An audible click from the FCA is normal when operating the key from the ON to the OFF position. REMOVAL 1. Remove electrical connector (6) from Fuel Control Actuator (FCA). 2. Remove FCA mounting screws (1). 3. Twist and pull FCA to remove from injection pump. INSTALLATION 1. Lubricate new Fuel Control Actuator (FCA) O-ring with clean oil before installation. 2. Turn FCA in a clockwise direction while pressing it into machined bore on rear of fuel injection pump. Be sure FCA flange is flush with the mounting surface on fuel injection pump. 3. Install FCA mounting screws (1) by hand. 4. Tighten FCA mounting screws (1) to 7 N·m (62 in. Ibs).

CRANKSHAFT POSITION SENSOR DESCRIPTION The Crankshaft Position Sensor (CKP) on the diesel engine is attached at the front / left side of the engine next to the engine harmonic balancer (crankshaft damper). OPERATION The Crankshaft Position Sensor (CKP) (5) is the primary engine speed indicator for the engine after the engine is running. The CKP contains a hall effect device. A rotating, notched target wheel (tone wheel) for the CKP is located behind the engine harmonic balancer (2). This has effect device detects notches located on the tone wheel. As the tone wheel rotates, the notches pass the tip of the CKP. When the leading edge of the tonewheel notch passes the tip of the CKP, the following occurs: The interruption of the magnetic field causes the voltage to switch high resulting in a signal of approximately 5 volts. When the trailing edge of the tonewheel notch passes the tip of the CKP, the following occurs: The change of the magnetic field causes the signal voltage to switch low to 0 volts. The Camshaft Position Sensor (CMP) also provides a signal to the Engine Control Module (ECM) at all times when the engine is running. The ECM uses this CMP information primarily on engine start-up. Once the engine is running, the ECM uses the CMP as a backup sensor for engine speed. REMOVAL 1. Raise and support vehicle 2. Disconnect electrical connector (4) at CKP sensor. 3. Remove 1 sensor mounting bolt (3). 4. Remove CKP sensor. INSTALLATION 1. Position and install CKP sensor (5) to engine. 2. Install 1 sensor mounting bolt and tighten to 9 N·m (80 in. Ibs.) torque. 3. Install electrical connector (4) to CKP sensor.

APPS (Accelerator Pedal Position Sensor) DESCRIPTION The Accelerator Pedal Position Sensor (APPS) is located inside the vehicle. It is attached to the accelerator pedal assembly. OPERATION The Accelerator Pedal Position Sensor (APPS) provides the Engine Control Module (ECM) with two DC voltage signals which change as the position of the accelerator pedal changes. One of the DC voltage signals will be half the voltage of the other signal. REMOVAL CAUTION: Do not attempt to separate or remove the Accelerator Pedal Position Sensor (APPS) from the accelerator pedal assembly. The APPS is replaced as an assembly along with the pedal. If sensor is removed from pedal, its electronic calibration may be destroyed. 1. Disconnect 6-way electrical connector at top of APPS (2). 2. Remove APPS lower mounting bolt (4) and two mounting nuts. 3. Remove pedal and APPS assembly from vehicle. INSTALLATION CAUTION: Do not attempt to separate or remove the Accelerator Pedal Position Sensor (APPS) from the accelerator pedal assembly. The APPS is replaced as an assembly along with the pedal. If sensor is removed from pedal, its electronic calibration may be destroyed. 1. Position pedal and APPS assembly to its mounting bracket. 2. Connect 6-way electrical connector to top of APPS (2). 3. Install APPS lower mounting bolt (4) and two mounting nuts. 4. If necessary. use a Scan Tool to erase any Diagnostic Trouble Codes (OTC's).