Engine Controls Self-Diagnostics - Diesel: Diagnosis Dodge Cab & Chassis R2500

SELF-DIAGNOSTIC SYSTEM

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. For ECM programming, see ENGINE CONTROL MODULE under PROGRAMMING.

Note. Self-diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRBIII®) scan tool, which will be referred to as DRB during testing procedures. A generic scan tool may not be capable of performing all necessary test functions.

ON-BOARD DIAGNOSTICS

Note. Malfunction Indicator Light (MIL) may also be referred to as CHECK ENGINE light.

MIL is located on instrument cluster, just below WATER-IN-FUEL light directly below the tachometer and is displayed as an engine icon. When ignition is first turned on, MIL should come on and remain on for 2 seconds to verify bulb and circuit operation, and then go off.

Note. If MIL does not come on and remain on for 2 seconds and then go off when ignition is first turned on, check instrument cluster for diagnosis of MIL. See ANALOG INSTRUMENT PANELS - RAM PICKUP article in ACCESSORIES & EQUIPMENT.

The Engine Control Module (ECM) and Powertrain Control Module (PCM) monitor several circuits and components in the powertrain system. ECM is used to control fuel and emission systems and PCM is used to primarily control charging system, transmission, A/C compressor clutch operation and vehicle speed control functions. If ECM or PCM senses a problem with a monitored circuit often enough to indicate a problem, a Diagnostic Trouble Code (DTC) will be stored in ECM or PCM. DTCs are the result of a system or circuit malfunction, but do not directly identify the failed component or components. If malfunction affects vehicle emissions, a DTC will be stored in ECM and MIL will be turned on and remain on steady and ECM will enter limp-in mode. In limp-in mode, the ECM substitutes values for failed component and provides continuous engine operation. If problem exists which does not affect vehicle emissions, a DTC will be stored in ECM or PCM but MIL will not be turned on. Certain DTCs may also store a companion DTC, meaning that if a certain DTC is stored in the ECM or PCM, the same DTC will be stored in the opposite control module. Any circuit or component that is associated with limp-in mode will cause a DTC to be stored in ECM and illuminate the MIL after one trip. Any circuit or component that is not associated with limp-in mode will cause DTC to be stored in ECM and illuminate the MIL after 2 trips. The ECM or PCM will turn off MIL when malfunction is not detected during 2 consecutive trips.

The ECM or PCM might not store a DTC for a monitored circuit even though a malfunction has occurred. This may happen because one of the criteria for DTC has not been met. For example, assume criteria for DTC requires ECM to monitor a specified circuit only when engine operates between 750 RPM and 2000 RPM. If the sensor output circuit becomes shorted to ground when engine is operating at 2400 RPM, DTC will not be stored, as short to ground occurred at 2400 RPM which exceeds the limit when the circuit was monitored.

DTCs may be retrieved for system diagnosis. See RETRIEVING DIAGNOSTIC TROUBLE CODES . System malfunctions are identified as either hard failures or intermittent failures. For additional information on hard failures or intermittent failures, see HARD FAILURES and INTERMITTENT FAILURES .

DIAGNOSTIC PROCEDURE

If no faults were found while performing basic diagnostic procedures, proceed with self-diagnostics. Always perform a visual inspection before attempting to diagnose engine control system problems. See VISUAL INSPECTION . Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES .

VISUAL INSPECTION

Most driveability problems in the engine control system result from faulty wiring, poor electrical connections, improper wire routing or leaking air and vacuum hose connections. Inspect all engine control system components, hoses, connectors and wiring for damage before proceeding with self-diagnostics. After completing visual inspection, retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES .

RETRIEVING DIAGNOSTIC TROUBLE CODES

Note. Ensure battery is fully charged before retrieving diagnostic trouble codes.

1. Ensure ignition off. Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. (Scheme 23)
2. Turn ignition on with engine off. Using scan tool manufacturer's instructions, read and record Diagnostic Trouble Code (DTC) code. Certain DTCs may also store a companion DTC, meaning that if a certain DTC is stored in the Engine Control Module (ECM) or Powertrain Control Module (PCM), the same DTC will be stored in the opposite control module. If DTCs are stored, identify DTC and perform appropriate test for displayed DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-97349-S11984774092001050200000). Once all repairs are made, ensure DTCs are cleared from ECM and PCM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-97349-S08700125602001050200000).
3. On any scan tool, if scan tool displays NO RESPONSE for ECM and/or PCM, perform appropriate procedure under «SCAN TOOL COMMUNICATIONS»(ref-97349-S23941622762001051500000). If scan tool will not power up, check for loose cable connections or bad cable. If cable connections or cable are defective, repair or replace components as necessary and then recheck for DTCs. If cable connections and cable are okay, using DVOM, measure voltage at cavity No. 16 (Pink wire) on DLC. Voltage should be at least 11 volts. If voltage is not as specified, check for defective fuse No. 12 (10-amp), as this fuse supplies voltage from battery to cavity No. 16 on DLC. Fuse No. 12 is located in junction block on end of driver's side of instrument panel, near door opening. If necessary, check wiring circuit between fuse No. 12 and the battery. See DATA LINK CONNECTORS and POWER DISTRIBUTION articles in WIRING DIAGRAMS. If voltage exists at cavity No. 16 (Pink wire) on DLC but scan tool will not power up and blank screen exists, it may be necessary to ensure that good ground exists at DLC terminals No. 4 (Black/Light Green wire) or No. 5 (Black/Tan wire). For ground circuit wiring, see GROUND DISTRIBUTION article in WIRING DIAGRAMS.
4. If scan tool display is not visible, try adjusting contrast. Low ambient temperatures will effect display screen.
5. If scan tool displays an error message, (i.e., USER-REQUESTED COLD BOOT or USER-REQUESTED WARM BOOT), follow scan tool manufacturer's instructions. If scan tool displays a bus failure, this indicates either a scan tool failure or bus failure. To diagnose and correct bus failures, see appropriate diagnostic and repair procedure under COMMUNICATIONS under SYSTEM TESTS in BODY CONTROL MODULES - RAM PICKUP article in ACCESSORIES & EQUIPMENT.
6. If no DTCs are displayed, refer to one of the following: For driveability problems, perform appropriate symptom test located in TROUBLE SHOOTING NO CODES - RAM PICKUP - DIESEL article. For no-start problems, perform appropriate no-start test in BASIC DIAGNOSTIC PROCEDURES - RAM PICKUP - DIESEL article. For individual system and component tests, perform appropriate procedure in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. For additional speed control problems and servicing information, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT. For additional charging system problems and servicing information, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.

Note. If MIL remains on steady and no DTCs exist, check instrument cluster for diagnosis of MIL. See ANALOG INSTRUMENT PANELS - RAM PICKUP article in ACCESSORIES & EQUIPMENT.

Scheme 23

Using Scan Tool

Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. (Scheme 23) Turn ignition on with engine off. Using screen prompts on scan tool, erase DTC from Engine Control Module (ECM) or Powertrain Control Module (PCM). Certain DTCs may also store a companion DTC, meaning that if a certain DTC is stored in the ECM or PCM, the same DTC will be stored in the opposite control module. It may be necessary to clear DTC from both ECM and PCM.

Self-Erasure

After 3 good trips, Powertrain Control Module (PCM) will turn off the MIL. At that time, the PCM will automatically switch the trip counter to a warm-up cycle counter. The PCM will erase DTCs after 40 warm-up cycles if the recent malfunction does not reoccur in that time. For additional information on good trips and warm-up cycles, see TRIP INDICATOR under ON-BOARD DIAGNOSTICS.

DIAGNOSTIC CIRCUIT CHECK

Note. This following procedures will check for proper power and ground supply to Engine Control Module (ECM) and Powertrain Control Module (PCM).

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE MESSAGES & CODES

DIAGNOSTIC TESTS

Note. Before diagnosing an engine performance problem, refer to SERVICE PRECAUTIONS under SELF-DIAGNOSTIC SYSTEM before proceeding.

Note. Before performing any testing procedures, check for any related technical service bulletins.

Note. Self-diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRBIII®) scan tool. A generic scan tool may not be capable of performing all necessary test functions.

Testing

1. Turn ignition on with engine off. Using scan tool, read IAT sensor voltage. If IAT sensor voltage is less than.5 volt, go to next step. If IAT sensor voltage is.5 volt or more, go to step 6.
2. Turn ignition off. Disconnect IAT sensor connector. IAT sensor is located on driver's side rear corner of cylinder head. (Scheme 24) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground and terminal "A" (Black/Light Blue wire) on IAT sensor connector. see scheme 19 If resistance is 100 k/ohms or more, go to next step. If resistance is less than 100 k/ohms, repair short to ground in Black/Light Blue wire between IAT sensor and ECM.
3. Ensure IAT sensor connector is still disconnected. Using DVOM, measure resistance between ground and IAT sensor connector terminal "B" (component side). If resistance is 100 k/ohms or more, go to next step. If resistance is less than 100 k/ohms, replace IAT sensor.
4. Ensure IAT sensor connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal "B" (Black/Red wire) on IAT sensor connector. If resistance is 100 k/ohms or more, go to next step. If resistance is less than 100 k/ohms, repair short to ground in Black/Red wire between IAT sensor and ECM.
5. Using DVOM, measure resistance between terminals on IAT sensor. If resistance is 175-244 k/ohms, replace ECM. If resistance is not 175-244 k/ohms, replace IAT sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition off. Inspect wiring and connectors between IAT sensor and ECM. IAT sensor is located on driver's side rear corner of cylinder head. (Scheme 24) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
7. Turn ignition on with engine off. Wiggle wiring harness and connectors between IAT sensor and ECM while monitoring IAT sensor voltage. If IAT sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If IAT sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
8. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect IAT sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect IAT sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

Scheme 24

1. Turn ignition on with engine off. Using scan tool, read IAT sensor voltage. If IAT sensor voltage is more than 4.5 volts, go to next step. If IAT sensor voltage is 4.5 volts or less, go to step 5.
2. Turn ignition off. Disconnect IAT sensor connector. IAT sensor is located on driver's side rear corner of cylinder head. (Scheme 24) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance of Black/Light Blue wire between terminal "A" on IAT sensor connector and terminal No. 11 on ECM connector. see scheme 12and see scheme 19. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Light Blue wire between IAT sensor and ECM.
3. Using DVOM, measure resistance between terminals on IAT sensor. If resistance is 175-244 k/ohms, go to next step. If resistance is not 175-244 k/ohms, replace IAT sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. Using DVOM, measure resistance of Black/Red wire between terminal "B" on IAT sensor connector and terminal No. 7 on ECM connector. If resistance is less than 5 ohms, replace ECM. If resistance is 5 ohms or more, repair open in Black/Red wire between IAT sensor and ECM.
5. Turn ignition on with engine off. Wiggle wiring harness and connectors between IAT sensor and ECM while monitoring IAT sensor voltage. IAT sensor is located on driver's side rear corner of cylinder head. (Scheme 24) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If IAT sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If IAT sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
6. Turn ignition off. Inspect wiring and connectors between IAT sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
7. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect IAT sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect IAT sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, read ECT sensor voltage. If ECT sensor voltage is less than.5 volt, go to next step. If ECT sensor voltage is.5 volt or more, go to step 6.
2. Turn ignition off. Disconnect ECT sensor connector. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) Using DVOM, measure resistance between ground and terminal "B" (Tan/Black wire) on ECT sensor connector. see scheme 13 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, replace ECT sensor.
3. Ensure ignition is off and ECT sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground and terminal "A" (Black/Light Blue wire) on ECT sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Black/Light Blue wire between ECT sensor and ECM.
4. Ensure ECT sensor connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal "B" (Tan/Black wire) on ECT sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Tan/Black wire between ECT sensor and ECM.
5. Using DVOM, measure resistance between terminals on ECT sensor. If resistance is 175-244 k/ohms, replace ECM. If resistance is not 175-244 k/ohms, replace ECT sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition on with engine off. Wiggle wiring harness and connectors between ECT sensor and ECM while monitoring ECT voltage. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If ECT sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If ECT sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
7. Turn ignition off. Inspect wiring and connectors between ECT sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
8. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect ECT sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect ECT sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

Scheme 25

1. Turn ignition on with engine off. Using scan tool, read ECT sensor voltage. If ECT sensor voltage is more than 4.5 volts, go to next step. If ECT sensor voltage is 4.5 volts or less, go to step 6.
2. Turn ignition off. Disconnect ECT sensor connector. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) Using DVOM, measure resistance between terminals on ECT sensor. If resistance is 175-244 k/ohms, go to next step. If resistance is not 175-244 k/ohms, replace ECT sensor.
3. Ensure ECT sensor connector is still disconnected. Start engine and allow engine to idle. Using DVOM, measure voltage at terminal "B" (Tan/Black wire) on ECT sensor connector. If voltage is 5.5 volts or less, go to next step. If voltage is more than 5.5 volts, repair short to voltage on Tan/Black wire between ECT sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.
4. Shut engine off. Ensure ignition is off and ECT sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal "A" (Black/Light Blue wire) on ECT sensor connector and terminal No. 11 (Black/Light Blue wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Light Blue wire between ECT sensor and ECM.
5. Using DVOM, measure resistance between terminal "B" (Tan/Black wire) on ECT sensor connector and terminal No. 14 (Tan/Black wire) on ECM connector. If resistance is less than 5 ohms, replace ECM. If resistance is 5 ohms or more, repair open in Tan/Black wire between ECT sensor and ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition on with engine off. Wiggle wiring harness and connectors between ECT sensor and ECM while monitoring ECT voltage. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If ECT sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If ECT sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
7. Turn ignition off. Inspect wiring and connectors between ECT sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
8. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect ECT sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect ECT sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Ensure ignition is off. Disconnect APPS connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Start engine and allow engine to idle. Using DVOM, measure voltage at terminal No. 5 (Dark Blue/White wire) on APPS connector. see scheme 4 If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 3.
2. Shut engine off. Turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 5 (Dark Blue/White wire) on APPS connector again. If voltage is more than 5.5 volts, repair short to voltage on Dark Blue/White wire between APPS and ECM when ignition is on. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If voltage is 5.5 volts or less, repair short to voltage on Dark Blue/White wire between APPS and ECM when engine is running.
3. Shut engine off. Ensure ignition is off and APPS connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 4 (Black/Yellow wire) on APPS connector. If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, replace APPS.
4. Start engine and allow engine to idle. Shut engine off. Turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If voltage is 4.5 volts or less, go to next step. If voltage is more than 4.5 volts, repair short to voltage on Light Green/Dark Blue wire between APPS and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.
5. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal No. 4 (Black/Yellow wire) on APPS connector and terminal No. 32 (Black/Yellow wire) on ECM connector. see scheme 4and see scheme 12. If resistance is 5 ohms or more, repair open in Black/Yellow wire between APPS and ECM. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

Scheme 26

1. Turn ignition on with engine off. Using scan tool, check for ECM and PCM DTCs. If DTC P0122 is stored in both ECM and PCM, go to next step. If DTC P0122 is not stored in both ECM and PCM, go to step 8.
2. Turn ignition off. Disconnect APPS sensor connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. see scheme 4 If voltage is more than 4.5 volts, go to next step. If voltage is 4.5 volts or less, go to step 7.
3. Turn ignition off. Ensure APPS connector is still disconnected. Measure resistance between terminal No. 4 (Black/Yellow wire) and terminal No. 5 (Dark Blue/White wire) on APPS connector. If resistance is greater than 5 ohms, go to next step. If resistance is 5 ohms or less, repair short between Dark Blue/White and Black/Yellow wires. The Black/Yellow wire is the sensor ground circuit.
4. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between ground and terminal No. 3 (Light Blue/Black wire) on APPS connector. If resistance is greater than 5 ohms, go to next step. If resistance is 5 ohms or less, repair short to ground in Light Blue/Black wire.
5. Ensure APPS and ECM connectors are still disconnected. Measure resistance between ground and terminal No. 5 (Dark Blue/White wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/White wire.
6. Turn ignition off. Ensure APPS connector is still disconnected. Reconnect ECM connector. Measure resistance between terminal No. 3 (Light Blue/Black wire) and terminal No. 4 (Black/Yellow wire) on APPS connector. If resistance is greater than 5 ohms, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or less, repair short between Light Blue/Black and Black/Yellow wire. The Black/Yellow wire is the sensor ground circuit.
7. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance in Dark Blue/White wire between terminal No. 5 on APPS connector and terminal No. 31 on ECM connector. see scheme 12 If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair Dark Blue/White wire.
8. Turn ignition off. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Measure resistance between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. see scheme 22 This is the APPS signal wire and goes to terminal No. 28 (Orange/Dark Blue wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 10.
9. Ensure PCM connectors are still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. If resistance is less than 5 ohms, repair short to ground in Orange/Dark Blue wire between ECM and PCM. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
10. Ensure ECM connector is still disconnected. Reconnect PCM connectors. Measure resistance between terminal No. 28 (Orange/Dark Blue wire) on ECM connector. If resistance is 5 ohms or more, go to next step. If open short to ground exists, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
11. Ensure APPS and ECM connectors are still disconnected. Measure resistance in Orange/Dark Blue wire between terminal No. 28 on ECM connector and terminal No. 23 on PCM connector C1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in open in Dark Blue/White wire between ECM and PCM.
12. Ensure PCM connectors are still disconnected. Reconnect ECM connector. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. If voltage is more than.4 volt, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is.4 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, read ECM and PCM DTCs. If DTC P0123 is stored in both ECM and PCM, go to next step. If DTC P0123 is not stored in both ECM and PCM, go to step 11.
2. Turn ignition off. Disconnect APPS sensor connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Start engine and allow engine to idle. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. see scheme 4 If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 5.
3. Shut engine off. Ensure APPS connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage on Dark Blue/White wire between APPS and ECM when engine is running. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
4. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If voltage is more than 5.5 volts, repair short to voltage on Dark Blue/White wire between APPS and ECM. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
5. Ensure APPS connector is still disconnected. and engine is idling. Using a DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 8.
6. Shut engine off. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage on Light Blue/Black wire between APPS and ECM when engine is running.
7. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is more than 5.5 volts, repair short to voltage on Light Blue/Black wire between APPS and ECM when ignition is on. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
8. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Measure resistance between terminal No. 4 (Black/Yellow wire) on APPS connector and terminal No. 32 (Black/Yellow wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Yellow wire between APPS and ECM.
9. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 3 (Light Blue/Black wire) on APPS connector and terminal No. 25 (Light Blue/Black wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Light Blue/Black wire between APPS and ECM.
10. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 5 (Dark Blue/White wire) on APPS connector and terminal No. 31 (Dark Blue/White wire) on ECM connector. If resistance is less than 5 ohms, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Dark Blue/White wire between APPS and ECM.
11. Turn ignition off. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Start engine and allow engine to idle. Using DVOM, measure voltage between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. see scheme 22 If voltage is more than 5.5 volts go to next step. If voltage is 5.5 volts or less, go to step 14.
12. Shut engine off. Ensure PCM connectors are still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage on Orange/Dark Blue wire between terminal No. 23 on PCM connector C1 and terminal No. 28 on ECM when engine is running.
13. Turn ignition off. Ensure PCM connectors are still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1. If voltage is more than 5.5 volts, repair short to voltage on Orange/Dark Blue wire between terminal No. 23 on PCM connector C1 and terminal No. 28 on ECM when ignition is on. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
14. Shut engine off. Ensure ignition is off and PCM connectors are still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Measure resistance between terminal No. 23 (Orange/Dark Blue wire) on PCM connector C1 and terminal No. 28 (Orange/Dark Blue wire) on ECM connector. If resistance is 5 ohms or more, repair open in Orange/Dark Blue wire between PCM and ECM. If resistance is less than 5 ohms, test is complete. Clear DTCs from both ECM and PCM.

1. Ensure ignition is off. Disconnect ECT sensor connector. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) Inspect ECT sensor connector for miswired, corroded, pushed out or damaged terminals. If terminals are not miswired, corroded, pushed out or damaged, go to next step. If terminals are miswired, corroded, pushed out or damaged, repair as necessary.
2. This test procedure will be invalid if thermostat is stuck open. Turn ignition on. Measure engine temperature near ECT sensor using an external temperature measuring device. (Scheme 25) Ensure engine temperature is less than 124°F (50°C). Using scan tool, monitor ECT sensor reading. If both temperature readings are within 10 percent of each other, go to next step. If both temperature readings are not within 10 percent of each other, replace ECT sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
3. Measure engine temperature near ECT sensor using an external temperature measuring device. Start engine and allow it to reach temperature greater than 180°F (82°C). Using scan tool, monitor ECT sensor reading. If both temperature readings are within 10 percent of each other, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If both temperature readings are not within 10 percent of each other, replace ECT sensor.

1. Ensure ignition is off. Disconnect ECT sensor connector. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) Inspect ECT sensor connector for miswired, corroded, pushed out or damaged terminals. If terminals are not miswired, corroded, pushed out or damaged, go to next step. If terminals are miswired, corroded, pushed out or damaged, repair as necessary.
2. This test procedure will be invalid if thermostat is stuck open. Turn ignition on. Measure engine temperature near ECT sensor using an external temperature measuring device. (Scheme 25) Ensure engine temperature is less than 124°F (50°C). Using scan tool, monitor ECT sensor reading. If both temperature readings are within 10 percent of each other, go to next step. If both temperature readings are not within 10 percent of each other, replace ECT sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
3. Measure engine temperature near ECT sensor using an external temperature measuring device. Start engine and allow it to reach temperature greater than 180°F (82°C). Using scan tool, monitor ECT sensor reading. If both temperature readings are within 10 percent of each other, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If both temperature readings are not within 10 percent of each other, replace ECT sensor.

1. Test operation of overflow valve located on fuel injection pump. (Scheme 27) See OVERFLOW VALVE under FUEL SYSTEM in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. If overflow valve operates properly, go to next step. If overflow valve is defective, replace overflow valve.
2. At this time, FPCM is assumed to be defective and must be replaced. FPCM is incorporated into fuel injection pump and is non-serviceable. Replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

Scheme 27

1. Turn ignition on with engine off. Disconnect WIF sensor connector and note operation of WATER-IN-FUEL light. WIF sensor is located at bottom of fuel filter/water separator on driver's side of engine, just behind fuel injection pump. (Scheme 28) WATER-IN-FUEL light is located on instrument panel, just below the tachometer. If WATER-IN-FUEL light is off, go to next step. If WATER-IN-FUEL light remains on, perform «DTC P0178: WATER IN FUEL SENSOR VOLTAGE TOO LOW»(ref-97349-S15869611582001050200000) test.
2. Turn ignition off. Note location of drain valve and drain hose on fuel filter/water separator. (Scheme 28) Place drain pan below drain hose. Pull handle on drain valve upward and allow water to drain from fuel filter/water separator. Release handle on drain valve. Reinstall WIF sensor connector. Turn ignition on with engine off and note operation of WATER-IN-FUEL light. If WATER-IN-FUEL light remains on, replace WIF sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If WATER-IN-FUEL light is off, test is complete.

Scheme 28

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1488 exists, perform «DTC P1488: AUXILIARY 5 VOLT OUTPUT TOO LOW»(ref-97349-S39663728042001050200000) test. If DTC P1488 does not exist, go to next step.
2. Check for DTCs. If DTC P0562 exists, perform «DTC P0562: CHARGING SYSTEM VOLTAGE TOO LOW»(ref-97349-S13768119612001050200000) test. If DTC P0562 does not exist, go to next step.
3. Ensure ignition is off. Disconnect WIF sensor connector. WIF sensor is located at bottom of fuel filter/water separator on driver's side of engine, just behind fuel injection pump. (Scheme 28) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground and terminal "B" (Dark Green/Red wire) on WIF sensor connector. see scheme 24 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Green/Red wire between WIF sensor and ECM.
4. Ensure ignition is off. Reinstall ECM connector. Ensure WIF sensor connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage at terminal "B" (Dark Green/Red wire) on WIF sensor connector. If voltage is not 4.75-5.25 volts, go to next step. If voltage is 4.75-5.25 volts, replace WIF sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
5. Turn ignition off. Disconnect ECM connector. Ensure WIF sensor connector is still disconnected. Using DVOM, measure resistance between terminals "A" (Black/Light Blue wire) and "B" (Dark Green/Red wire) on WIF sensor connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Black/Light Blue wire and Dark Green/Red wire between ECM and WIF sensor as they are shorted together.

1. Turn ignition on with engine off. Using scan tool, clear DTCs. Start engine and allow engine to idle for one minute. Using scan tool, check for DTCs. If DTC P0180 does not exist, go to next step. If DTC P0180 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Shut engine off. Turn ignition on with engine off. Using scan tool, check for DTCs with engine off. If DTC P0180 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If DTC P0180 does not exist, test is complete.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0181 does not exist, go to next step. If DTC P0181 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Ensure ignition is on with engine off. Using scan tool, clear DTCs. Start engine and allow engine to idle for one minute. Using scan tool, check for DTCs. If DTC P0181 does not exist, test is complete. If DTC P0181 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is equal to zero, go to step 3 .
2. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, test is complete.
3. Using scan tool, check for DTCs. If DTC P1287 or P1690 is present, perform «DTC P1287: FUEL INJECTION PUMP CONTROLLER SUPPLY VOLTAGE LOW»(ref-97349-S17744611572001050200000) , or «DTC P1690: FUEL INJECTION PUMP CKP SENSOR DOES NOT AGREE WITH ECM CKP SENSOR»(ref-97349-S20401796222001050200000) test. If none of DTCs listed exist, go to next step.
4. Check for proper fuel injection pump timing and alignment of fuel injection pump drive gear. See FUEL INJECTION PUMP TIMING in ON-VEHICLE ADJUSTMENTS - RAM PICKUP - DIESEL article. If proper fuel injection pump timing and alignment of fuel injection pump drive gear exists, go to next step. If fuel injection pump timing and alignment of fuel injection pump drive gear is not correct, adjust as necessary.
5. Check fuel pressure drop across fuel filter. See FUEL PRESSURE DROP under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - RAM PICKUP - DIESEL article. If fuel pressure drop is as specified, go to next step. If fuel pressure drop is not as specified, check for restriction and repair as necessary.
6. Check transfer pump inlet for a restriction. See TRANSFER PUMP under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - RAM PICKUP - DIESEL article. If transfer pump inlet restriction is acceptable, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If transfer pump inlet restriction is not acceptable, repair transfer pump inlet line restriction.

Start engine and warm engine to normal operating temperature. Using temperature probe, check engine temperature near ECT sensor. ECT sensor is located at front of cylinder head, near thermostat housing. (Scheme 25) Using scan tool, read engine coolant temperature. If engine temperature and engine coolant temperature displayed on scan tool are not within 10°F of each other, perform DTC P0117: ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE TOO LOW test. If engine temperature and engine coolant temperature displayed on scan tool are within 10°F of each other, ECT sensor is operating properly. Check for any cooling system problems.

1. Ensure ignition is off. Disconnect APPS connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Start engine and allow engine to idle. Using DVOM, measure voltage between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. see scheme 4 This is the IVS No. 1 circuit. If voltage is more than 4.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 8.
2. With engine idling, using DVOM, measure voltage between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. This is the IVS No. 2 circuit. If voltage is 4.5 volts or less, go to next step. If voltage is more than 4.5 volts, shut engine off and go to step 13.
3. Shut engine off. Measure resistance between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 7.
4. Ensure ignition is off and APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Light Green/Dark Blue wire between APPS and ECM.
5. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 2 (Light Green/Dark Blue wire) and terminal No. 4 (Black/Yellow wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is 5 ohms or less, repair short in wiring as necessary.
6. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 2 (Light Green/Dark Blue wire) and terminal No. 1 (Black/Light Blue wire) on APPS connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or less, repair short in wiring as necessary.
7. Ensure ignition is off and APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 2 (Light Green/Dark Blue wire) on APPS connector and terminal No. 16 (Light Green/Dark Blue wire) on ECM connector. see scheme 12 If resistance is less than 5 ohms, go step 13. If resistance is 5 ohms or more, repair open in Light Green/Dark Blue wire between APPS and ECM.
8. Shut engine off. Ensure APPS connector is still disconnected. Measure resistance between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 12.
9. Ensure ignition is off and APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 6 (Brown/Orange wire) and terminal No. 1 (Black/Light Blue wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is 5 ohms or less, repair short in wiring as necessary.
10. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 6 (Brown/Orange wire) and terminal No. 4 (Black/Yellow wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is 5 ohms or less, repair short in wiring as necessary.
11. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Brown/Orange wire between APPS and ECM.
12. Ensure ignition is off and APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 6 (Brown/Orange wire) on APPS connector and terminal No. 1 (Brown/Orange wire) on ECM connector. see scheme 12 If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Brown/Orange wire between APPS and ECM.
13. Ensure ignition is off and APPS connector is still disconnected. Measure resistance between terminals No. 2 and 6 on APPS connector (component side). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace APPS sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
14. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 1 (Black/Light Blue wire) on APPS connector and terminal No. 11 (Black/Light Blue wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Light Blue wire between APPS and ECM.
15. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 6 (Brown/Orange wire) and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If resistance is 5 ohms or more, test is complete. If resistance is 5 ohms or less, repair short in wiring as necessary.

1. Ensure ignition is off. Disconnect APPS connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Start engine and allow engine to idle. Using DVOM, measure voltage between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. see scheme 4 This is the IVS No. 1 circuit. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 4.
2. Shut engine off. Ensure APPS connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage Brown/Orange wire between APPS and ECM when engine is running. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
3. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 6 (Brown/Orange wire) on APPS connector. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is more than 5.5 volts, repair short to voltage Brown/Orange wire between APPS and ECM when ignition is on.
4. With engine idling, using DVOM, measure voltage between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. This is the IVS No. 2 circuit. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 7.
5. Shut engine off. Turn ignition on with engine off. Ensure APPS connector is still disconnected. Using DVOM, measure voltage between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage on Light Green/Dark Blue wire between APPS and ECM when engine is running.
6. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 2 (Light Green/Dark Blue wire) on APPS connector. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is more than 5.5 volts, repair short to voltage on Light Green/Dark Blue wire between APPS and ECM when ignition is on.
7. Ensure ignition is off and APPS connector is still disconnected. Measure resistance between cylinder block and terminal No. 4 (Black/Yellow wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
8. Ensure ignition is off and APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 1 (Black/Light Blue wire) on APPS connector and terminal No. 11 (Black/Light Blue wire) on ECM connector. Measure resistance between terminal No. 4 (Black/Yellow wire) on APPS connector and terminal No. 32 (Black/Yellow wire) on ECM connector. If resistance is less than 5 ohms on all circuits, go to next step. If resistance is 5 ohms or more on any circuit, repair open wire between APPS and ECM.
9. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 6 (Brown/Orange wire) on APPS connector and terminal No. 1 (Brown/Orange wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Brown/Orange wire between APPS and ECM.
10. Measure resistance between terminal No. 2 (Light Green/Dark Blue wire) on APPS connector and terminal No. 16 (Light Green/Dark Blue wire) on ECM connector. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Light Green/Dark Blue wire between APPS and ECM.

1. Turn ignition off. Disconnect fuel transfer pump connector. Fuel transfer pump is located at driver's side of engine, just above the starter. (Scheme 29) Using DVOM, measure resistance between cylinder block and terminal No. 2 (Black/White wire) on component side of fuel transfer pump connector. see scheme 18 If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, fuel transfer pump is shorted. Replace fuel transfer pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Using DVOM, measure resistance between ground and terminal No. 2 (Black/White wire) on wiring harness side of fuel transfer pump connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/White wire between fuel transfer pump and ground connection. Ground connection is located on cylinder block, just below fuel transfer pump.
3. Using DVOM, measure resistance between cylinder block and terminal No. 1 (Yellow/White wire) on component side of fuel transfer pump connector. If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, fuel transfer pump is shorted. Replace fuel transfer pump.
4. Ensure ignition is off and fuel transfer pump connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal No. 1 (Yellow/White wire) on fuel transfer pump connector and terminal No. 15 (Yellow/White wire) on ECM connector. see scheme 12 If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Yellow/White wire between ECM and fuel transfer pump.
5. Ensure fuel transfer pump connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Yellow/White wire) on fuel transfer pump connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Yellow/White wire between ECM and fuel transfer pump.
6. Ensure ignition is off. Reinstall fuel transfer pump connector and ECM connector. Using 12-volt test light and Miller Tool Probe (6801), backprobe terminal No. 1 (Yellow/White wire) on transfer pump connector. While observing test light operation, turn ignition on with engine off. If test light does not momentarily illuminate brightly, turn ignition off and go to next step. If test light momentarily illuminates brightly, replace fuel transfer pump.
7. Ensure ignition is off. Disconnect fuel transfer pump connector. Using DVOM, measure resistance between terminals No. 1 (Yellow/White wire) and No. 2 (Black/White wire) on component side of fuel transfer pump connector. If resistance is 1.9-2.3 ohms, replace ECM. If resistance is not 1.9-1.3 ohms, replace fuel transfer pump.

Scheme 29

Ensure ignition is off. Disconnect Fuel Pump Control Module (FPCM) connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. Turn ignition on with engine off. Using DVOM, measure voltage at terminal No 5 (Light Blue/Red wire) on FPCM connector. see scheme 16 This is the fuel shutoff signal. Voltage should be 9-14.5 volts. If voltage is within specification, conditions required to set DTC are not present at this time. Test is complete. If voltage is not within specification, it is assumed that ECM is defective and should be replaced. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. Before installing replacement ECM, ensure all DTCs have been repaired to prevent damaging replacement ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2

Scheme 30

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is equal to zero, replace wastegate. It may be necessary to replace turbocharger and wastegate as an assembly. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Ensure ignition is on with engine off. Using scan tool, read and record FREEZE FRAME data. Road test vehicle under conditions displayed in FREEZE FRAME data and note DTC SPECIFIC GOOD TRIP counter. If DTC SPECIFIC GOOD TRIP counter does not change to zero, test is complete. If DTC SPECIFIC GOOD TRIP counter changes to zero, replace wastegate. It may be necessary to replace turbocharger and wastegate as an assembly.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0237, P0238 or P1475 exists, perform «DTC P0237: MAP SENSOR VOLTAGE TOO LOW»(ref-97349-S25610585372001050200000), «DTC P0238: MAP SENSOR VOLTAGE TOO HIGH»(ref-97349-S35331885142001050200000), or «DTC P1475: AUXILIARY 5 VOLT OUTPUT TOO HIGH»(ref-97349-S27905557912001050200000) test as required. If none of DTCs listed exist, go to next step.
2. Turn ignition off. Perform turbocharger boost pressure test. See TURBOCHARGER under AIR INDUCTION SYSTEMS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. If boost pressure is not within specification, repair as necessary. If boost pressure is within specification, go to next step.
3. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 Turn ignition on with engine off. Using DVOM, measure voltage between engine ground and terminal "A" (Orange wire) on MAP sensor connector. see scheme 20 If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair Orange wire between MAP sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
4. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using DVOM, measure voltage between terminals "A" (Orange wire) and "B" (Black/Light Blue wire) on MAP sensor connector. If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair open in Black/Light Blue wire between MAP sensor and ECM.
5. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is.42-.58 volt, go to next step. If MAP sensor voltage is not.42-.58 volt, replace MAP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal "C" (Gray/Red wire) on MAP sensor connector and terminal No. 8 (Gray/Red wire) on ECM connector. see scheme 12and see scheme 20. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Red wire between MAP sensor and ECM.
7. Using DVOM, measure resistance between ground and terminal "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray/Red wire between MAP sensor and ECM.
8. Using DVOM, measure resistance between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair Black/Light Blue wire and Gray/Red wire between ECM and MAP sensor as they are shorted together.
9. Using DVOM, measure resistance between terminals "A" (Orange wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance less than 5 ohms, repair Orange wire and Gray/Red wire between ECM and MAP sensor as they are shorted together.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1488 does not exist, go to next step. If DTC P1488 exists, perform «DTC P1488: AUXILIARY 5 VOLT OUTPUT TOO LOW»(ref-97349-S39663728042001050200000) test.
2. Start engine and allow engine to idle. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is.2 volt or more, go to next step. If MAP sensor voltage is less than.2 volt, go to step 4.
3. Shut engine off. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than 2.35 volts, go to next step. If MAP sensor voltage is 2.35 volts or more, go to step 9.
4. Turn ignition off. Perform turbocharger boost pressure test. See TURBOCHARGER under AIR INDUCTION SYSTEMS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. If boost pressure is not within specification, repair as necessary. If boost pressure is within specification, go to next step.
5. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector. see scheme 20 If voltage is more than 4.5 volts, go to next step. If voltage is 4.5 volts or less, repair open in Orange wire between ECM and MAP sensor. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.
6. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground and terminal "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray/Red wire between MAP sensor and ECM.
7. Ensure ignition is off. Reinstall ECM electrical connector. Ensure MAP sensor connector is still disconnected. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is 4.5 volts or less, go to next step. If MAP sensor voltage is more than 4.5 volts, replace MAP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
8. Turn ignition off. Disconnect ECM connector. Using DVOM, measure resistance between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair Black/Light Blue wire and Gray/Red wire between ECM and MAP sensor as they are shorted together.
9. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
10. Turn ignition off. Inspect wiring and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
11. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect MAP sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect MAP sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0113 or P0118 exists, perform «DTC P0113: INTAKE AIR TEMPERATURE SENSOR VOLTAGE TOO HIGH»(ref-97349-S41258136312001050200000) or «DTC P0118: ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE TOO HIGH»(ref-97349-S21704820622001050200000) test. If these DTC do not exist, go to next step.
2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. If no sensor supply voltage too high DTCs are set, go to next step. If DTC P0523 exist, go to «DTC P0523: OIL PRESSURE VOLTAGE TOO HIGH»(ref-97349-S06483141842001050200000) test. If any other sensor supply voltage too high DTCs exist, perform appropriate test for specified DTC. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-97349-S11984774092001050200000).
3. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than 5.5 volts, go to next step. If MAP sensor voltage is 5.5 volts or more, go to step 7.
4. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
5. Turn ignition off. Conditions required to set DTC are not present at this time. Inspect wiring and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
6. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect MAP sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect MAP sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.
7. Turn ignition off. Perform turbocharger boost pressure test. See TURBOCHARGER under AIR INDUCTION SYSTEMS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. If boost pressure is not within specification, repair as necessary. If boost pressure is within specifications, go to next step.
8. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 Turn ignition on with engine off. Using DVOM, measure voltage at terminal "C" (Gray/Red wire) on MAP sensor connector. see scheme 20 If voltage is 5.5 volts or less, go to next step. If voltage is more than 5.5 volts, repair short to voltage on Gray/Red wire between MAP sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
9. Turn ignition off. Ensure MAP sensor connector is still disconnected. Connect jumper wire between cylinder block and terminal "C" (Gray/Red wire) on MAP sensor connector. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is one volt or more, remove jumper wire and go to next step. If MAP sensor voltage is less than one volt, remove jumper wire and repair open in Black/Light Blue wire between MAP sensor and ECM.
10. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. Using DVOM, measure resistance between terminal "C" (Gray/Red wire) on MAP sensor connector and terminal No. 8 (Gray/Red wire) on ECM connector. see scheme 12and see scheme 33. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Red wire between MAP sensor and ECM.
11. Ensure ignition is off. Reinstall ECM connector. Ensure MAP sensor connector is still disconnected. Connect jumper wire between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than one volt, remove jumper wire and replace MAP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If MAP sensor voltage is one volt or more, remove jumper wire and replace ECM.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1284 does not exist, go to next step. If DTC P1284 exists, perform «DTC P1284: FUEL INJECTOR PUMP BATTERY VOLTAGE OUT OF RANGE»(ref-97349-S15927666822001050200000) test.
2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is equal to zero, go to step 5.
3. Ensure ignition is on with engine off. Using scan tool, read FREEZE FRAME data. Operate vehicle within FREEZE FRAME data parameters while wiggling wiring harness and connectors between Fuel Pump Control Module (FPCM) and ECM, and between fuel pump relay and FPCM. FPCM is located on end of fuel injection pump. (Scheme 30) FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Fuel pump relay is located in PDC at driver's side front corner of engine compartment. see scheme 30 Fuel pump relay may also be referred to as fuel injection pump relay. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, go to step 13.
4. Turn ignition off. Inspect wiring and connectors between FPCM and ECM, and between fuel pump relay and FPCM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
5. Check charging system operation. If charging system is operating properly, go to next step. If charging system is not operating properly, perform CHARGING SYSTEM test under MISCELLANEOUS CONTROLS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article.
6. Ensure ignition is off. Using DVOM, measure voltage between battery terminals. If voltage is 12 volts or more, go to next step. If voltage is less than 12 volts, recharge or replace battery as necessary.
7. Ensure ignition is off. Disconnect FPCM connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) Turn ignition on with engine off. Using 12-volt test light, check for voltage at terminal No. 7 (Red/Light Green wire) on FPCM connector. see scheme 16 If test light illuminates brightly, go to next step. If test light does not illuminate brightly, go to step 9.
8. Turn ignition off. Ensure FPCM connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 6 (Black/Tan wire) on FPCM connector. If resistance is less than 5 ohms, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Black/Tan wire between FPCM and ECM.
9. Turn ignition off. Remove fuel pump relay from Power Distribution Center (PDC). see scheme 30 PDC is located at driver's side front corner of engine compartment. see scheme 3 Fuel pump relay may also be referred to as fuel injection pump relay. Turn ignition on with engine off. Using 12-volt test light, check for voltage at cavity No. 86 (Brown/White wire) in PDC for fuel pump relay. see scheme 30 If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open in Brown/White wire between terminal No. 36 on ECM connector and cavity No. 86 in PDC for fuel pump relay.
10. Turn ignition off. Using DVOM, measure resistance between ground and cavity No. 85 (Black wire) in PDC for fuel pump relay. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between cavity No. 85 (Black wire) in PDC for fuel pump relay and ground connection. Ground connection is located on cylinder block, just below fuel transfer pump.
11. Using 12-volt test light, check for voltage at cavity No. 30 (Red/White wire) in PDC for fuel pump relay. This is the fused B+ circuit from battery to fuel pump relay. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open in Red/White wire between cavity No. 30 in PDC for fuel pump relay and fuse No. 3 (20-amp). Fuse No. 3 receives constant battery voltage and is located in PDC.
12. Using DVOM, measure resistance between cavity No. 87 (Red/Light Green wire) in PDC for fuel pump relay and terminal No. 7 (Red/Light Green wire) on FPCM connector. If resistance is less than 5 ohms, replace fuel pump relay. If resistance is 5 ohms or more, repair open in Red/Light Green wire between FPCM connector and cavity No. 87 (Red/Light Green wire) in PDC for fuel pump relay.
13. Turn ignition off. Inspect wiring and connectors between FPCM and ECM, and between fuel pump relay and FPCM. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary.

Turn ignition on. Using scan tool, erase any ECM DTCs. Test drive vehicle. Recheck for ECM DTCs. If DTC P0252 resets, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If DTC P0252 does not reset, test is complete.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is equal to zero, go to step 4.
2. Turn ignition off. Inspect wiring harness and connectors between Fuel Pump Control Module (FPCM) and ECM, and between fuel pump relay and FPCM. FPCM is located on top of fuel injection pump. (Scheme 30) FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Fuel pump relay is located in PDC at driver's side front corner of engine compartment. see scheme 30 Fuel pump relay may also be referred to as fuel injection pump relay. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
3. Turn ignition on with engine off. Using scan tool, read FREEZE FRAME data. Operate vehicle within FREEZE FRAME data parameters while wiggling wiring harness and connectors between FPCM and ECM, and between fuel pump relay and FPCM. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, test is complete.
4. Ensure ignition is on with engine off. Using scan tool, check for DTCs. If DTC P0215 does not exist, go to next step. If DTC P0215 exists, perform «DTC P0215: FUEL INJECTION PUMP CONTROL CIRCUIT»(ref-97349-S42573244632001050200000) test.
5. Turn ignition off. Using DVOM, measure voltage between battery terminals. If voltage is 12 volts or more, go to next step. If voltage is less than 12 volts, recharge or replace battery as necessary.
6. Ensure ignition is off. Disconnect FPCM connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. Using 12-volt test light connected to battery voltage, check for voltage at terminal No. 6 (Black/Tan wire) on FPCM connector. see scheme 16 If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open or high resistance on Black/Tan wire between FPCM and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
7. Ensure ignition is off and FPCM connector is still disconnected. Turn ignition on with engine off. Using 12-volt test light, check for voltage at terminal No. 7 on FPCM connector. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open or high resistance on Red/Light Green wire between FPCM connector and cavity No. 87 (Red/Light Green wire) in PDC for fuel pump relay. see scheme 30
8. Perform starter draw test with starter installed. Starter draw should be 450-700 amps. If starter draw is not within specification, repair or replace starter. If starter draw is within specification, using DVOM, measure voltage between battery terminals while cranking engine. If voltage is 8 volts or more, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is less than 8 volts, recharge or replace battery as necessary.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0254 does not exist, go to next step. If DTC P0254 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Turn ignition on with engine off. Using scan tool, clear DTCs. Start engine and allow engine to idle for one minute. Using scan tool, check for DTCs. If DTC P0254 does not exist, test is complete. If DTC P0254 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to step 6.
2. Check engine for mechanical problems such as damaged valves, push rods, or rocker arms, etc. If no engine mechanical problems exist, go to next step. If engine mechanical problems exist, repair engine as necessary.
3. Ensure ignition is off. Using scan tool in lab scope mode, connect lab scope lead to terminal "C" (Gray wire) on CMP sensor connector. CMP sensor is located on driver's side of cylinder block, below fuel injection pump. (Scheme 31) Start engine and allow engine to idle. Check CMP sensor pattern in 10 millisecond range. If CMP sensor pattern is irregular, go to next step. If CMP sensor pattern is okay, go to step 5.
4. Shut engine off. Disconnect negative battery cables. Remove starter for access to CMP sensor. Remove retaining bolt and CMP sensor. Inspect tone wheel for CMP sensor for damage. If tone wheel is okay, replace CMP sensor. If tone wheel is defective, replace tone wheel.
5. With engine idling and using lab scope to monitor CMP sensor pattern, wiggling wiring harness and connectors from CMP sensor to ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If CMP sensor pattern changes while wiggling wiring harness and connectors, repair wiring harness or connector as necessary. If CMP sensor pattern does not change while wiggling wiring harness and connectors, check for damaged ECM or Powertrain Control Module (PCM) terminals, engine mechanical problem, faulty connections, defective fuel injector(s), defective fuel line(s) or defective fuel injection pump. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Repair or replace components as necessary.
6. Ensure ignition is on with engine off. Using scan tool, check for DTCs. Check that displayed DTC matches the FREEZE FRAME DTC. If DTCs are the same, go to next step. If DTCs displayed are not the same, perform procedures for FREEZE FRAME DTC. Also check for additional DTCs and repair as necessary.
7. Ensure ignition is on with engine off. Using scan tool, read and record FREEZE FRAME data. Road test vehicle under conditions displayed in FREEZE FRAME data parameters and pay particular attention to DTC setting conditions such as speed, temperature and load. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter changes to zero, perform fuel delivery test. Go to FUEL DELIVERY under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article. If DTC SPECIFIC GOOD TRIP counter does not change to zero, operate vehicle for one MISFIRE GOOD TRIP and then clear DTCs.

Scheme 31

1. Start engine and allow engine to idle. Using scan tool, read engine speed at PCM. Compare engine speed displayed on scan tool with engine speed on tachometer. If engine speed on scan tool is not within 100 RPM of engine speed on tachometer, go to next step. If engine speed on scan tool is within 100 RPM of engine speed on tachometer, DTC is inactive at this time. Shut engine off. Inspect ECM and PCM for damaged pins or terminals. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Repair or replace components as necessary.
2. Shut engine off. Ensure ignition is off. Using DVOM, backprobe terminal No. 8 (Gray/Black wire) on PCM connector C1. see scheme 22 This is the Camshaft Position (CMP) sensor signal circuit at PCM. Turn ignition on with engine off and note voltage reading. If voltage is more than 4.75 volts, leave DVOM connected and go to next step. If voltage is 4.75 volts or less, go to step 6.
3. Turn ignition off. Ensure DVOM is still backprobing terminal No. 8 (Gray/Black wire) on PCM connector C1. Start engine and allow engine to idle. Note voltage reading with engine idling. If voltage is not 2-3 volts, leave DVOM connected and go to next step. If voltage is 2-3 volts, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. Shut engine off. Ensure ignition is off. Ensure DVOM is still backprobing terminal No. 8 (Gray/Black wire) on PCM connector C1. Turn ignition on with engine off and note voltage reading. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage on Gray/Black wire between terminal No. 45 on ECM connector and terminal No. 8 on PCM connector C1.
5. Turn ignition off. Disconnect ECM and PCM connectors. Using DVOM, measure resistance on Gray/Black wire between terminal No. 45 on ECM connector and terminal No. 8 on PCM connector C1. If resistance is less than 5 ohms, replace ECM. If resistance is 5 ohms or more, repair open in Gray/Black wire between ECM and PCM.
6. Turn ignition off. Disconnect ECM and PCM connectors. Using DVOM, measure resistance between ground and terminal No. 45 (Gray/Black wire) on ECM connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Gray/Black wire between ECM and PCM.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, check for intermittent connections and repair as necessary. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step.
2. Turn ignition off. Disconnect CMP sensor connector. (Scheme 31) Turn ignition on. Using DVOM, measure voltage at terminal "C" (Gray wire) on CMP sensor connector. see scheme 7 If voltage is 4.5 volts or more, go to next step. If voltage is less than 4.5 volts, go to step 6.
3. Using DVOM, measure voltage at terminal "A" (Violet/White wire) on CMP sensor connector. If voltage is 4.5 volts or more, go to next step. If voltage is less than 4.5 volts, go to step 9.
4. Turn ignition off. Ensure CMP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance of Black/Dark Blue wire between terminal "B" on CMP sensor connector and terminal No. 4 on ECM connector. see scheme 7and see scheme 12. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Dark Blue wire between CMP sensor and ECM.
5. Connect one end of a fused jumper wire to CMP sensor connector terminal "C" (Gray wire). Using scan tool, monitor CMP sensor RPM while tapping other end of fused jumper wire to CMP sensor connector terminal "B" (Black/Dark Blue wire). If CMP sensor RPM changes, replace CMP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If CMP sensor RPM does not change, replace ECM.
6. Turn ignition off. Ensure CMP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance of Gray wire between terminal "C" on CMP sensor connector and terminal No. 17 on ECM connector. see scheme 7and see scheme 12. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray wire between CMP sensor and ECM.
7. Using DVOM, measure resistance between ground and terminal "C" (Gray wire) on CMP sensor connector. If resistance is 1000 ohms or more, go to next step. If resistance is less than 1000 ohms, repair short to ground in Gray wire between CMP sensor and ECM.
8. Using DVOM, measure resistance between terminal "B" (Black/Dark Blue wire) and terminal "C" (Gray wire) on CMP sensor connector. If resistance is 1000 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 1000 ohms, repair short between Black/Dark Blue and Gray wire between CMP sensor and ECM.
9. Turn ignition off. Ensure CMP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance of Violet/White wire between terminal "A" on CMP sensor connector and terminal No. 3 on ECM connector. see scheme 7and see scheme 12. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Violet/White wire between CMP sensor and ECM.
10. Using DVOM, measure resistance between ground and terminal "A" (Violet/White wire) on CMP sensor connector. If resistance is 1000 ohms or more, go to next step. If resistance is less than 1000 ohms, repair short to ground in Violet/White wire between CMP sensor and ECM.
11. Using DVOM, measure resistance between terminal "A" (Violet/White wire) and terminal "B" (Black/Dark Blue wire) on CMP sensor connector. If resistance is 1000 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 1000 ohms, repair short between Violet/White and Black/Dark Blue wire between CMP sensor and ECM.

1. Turn ignition off. Locate and disconnect CMP sensor. CMP sensor is located on left side of engine, below fuel injection pump. Turn ignition on. Using DVOM, measure voltage at terminal "A" (Violet/White wire) at CMP sensor connector. see scheme 7 If voltage is less than 4.2 volts, go to next step. If voltage is 4.2 volts or more, test is complete.
2. Turn ignition off. Ensure CMP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground and terminal "A" (Violet/White wire) on CMP sensor connector. If resistance is 1000 ohms or more, go to next step. If resistance is less than 1000 ohms, repair short to ground in Violet/White wire between CMP sensor and ECM.
3. Check for damage to wiring and connectors. Repair as necessary. If wiring and connectors are okay, replace CMP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition off. Locate and disconnect CMP sensor. CMP sensor is located on left side of engine, below fuel injection pump. Turn ignition on. Using DVOM, measure voltage at terminal "A" (Violet/White wire) at CMP sensor connector. see scheme 7 If voltage is 5.5 volts or more, go to next step. If voltage is less than 5.5 volts, test is complete.
2. Turn ignition off. Ensure CMP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on. Using DVOM, measure voltage at terminal "A" (Violet/White wire) on CMP sensor connector. If voltage is 5.5 volts or more, repair short to voltage in Violet/White wire. If voltage is less than 5.5 volts, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0370 does not exist, go to next step. If DTC P0370 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Ensure ignition is on with engine off. Using scan tool, clear DTCs. Start engine and allow engine to idle for one minute. Using scan tool, check for DTCs. If DTC P0370 does not exist, test is complete. If DTC P0370 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 5.
2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. Check that displayed DTC matches the FREEZE FRAME DTC. If DTC matches the FREEZE FRAME DTC, go to next step. If DTC does not match the FREEZE FRAME DTC, perform procedures for FREEZE FRAME DTC. Also check for additional DTCs and repair as necessary.
3. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter does not change to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to step 5. NOTE: Keep air intake heater actuation time to a minimum due to high current draw.
4. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 1 and note battery voltage. DO NOT actuate intake air heater No. 1 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 1. If battery voltage drops less than.5 volt when intake air heater No. 1 is actuated, go to next step. If battery voltage drops.5 volt or more when intake air heater No. 1 was actuated, intake air heater relay No. 1 is operating properly. Test is complete.
5. Turn ignition off. Disconnect intake air heater relay No. 1 control circuit connector (Yellow/Black wire). Intake air heater relays are located on bracket near driver's side battery. (Scheme 32) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground terminal No. 29 (Yellow/Black wire) on ECM connector. see scheme 12 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Yellow/Black wire between ECM and intake air heater relay No. 1.
6. Ensure ignition is off. Disconnect ground circuit connector (Black/Tan wire) at intake air heater relay No. 1. (Scheme 32) Using DVOM, measure resistance between ground and ground circuit connector (Black/Tan wire) for intake air heater relay No. 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Tan wire between intake air heater relay No. 1 and ground connection. Ground connection is located at ground connection for negative battery terminal.
7. Reinstall ground circuit connector (Black/Tan wire) at intake air heater relay No. 1. Ensure intake air heater relay No. 1 control circuit connector (Yellow/Black wire) is disconnected at intake air heater relay No. 1. Connect one end of jumper wire to intake air heater relay No. 1 control circuit connector (Yellow/Black wire) terminal on intake air heater relay No. 1. Momentarily touch other end of jumper wire to battery voltage while listening for operating sound (click) at intake air heater relay No. 1. If operating sound is heard at intake air heater relay No. 1, remove jumper wire and go to next step. If operating sound is not heard at intake air heater relay No. 1, remove jumper wire. Replace intake air heater relay No. 1.
8. Ensure intake air heater relay No. 1 control circuit connector (Yellow/Black wire) is disconnected at intake air heater relay No. 1 and ECM connector is still disconnected. Using DVOM, measure resistance between intake air heater relay No. 1 control circuit connector (Yellow/Black wire) at intake air heater relay No. 1 and terminal No. 29 (Yellow/Black wire) on ECM connector. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Yellow/Black wire between intake air heater relay No. 1 and ECM.

Scheme 32

1. Ensure ignition is off. While monitoring WAIT-TO-START light operation, turn ignition on with engine off. WAIT-TO-START light is located on instrument cluster, directly below the speedometer and CHECK GAGES light. If WAIT TO START light illuminates, go to next step. If WAIT TO START light does not illuminate, go to step 4.
2. Turn ignition off. While monitoring WAIT-TO- START light operation, turn ignition on with engine off. If WAIT-TO-START light stays on all the time, go to next step. If WAIT-TO- START light illuminates and then goes off, WAIT-TO-START light is operating properly. Test is complete.
3. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 While monitoring WAIT-TO-START light operation, turn ignition on with engine off. If WAIT-TO-START light illuminates, repair short to ground in Orange/Black wire between ECM and WAIT-TO-START light. If WAIT-TO- START light does not illuminate, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Connect jumper wire between ground and terminal No. 37 (Orange/Black wire) on ECM connector. see scheme 12 Turn ignition on with engine off and note operation of WAIT-TO-START light. If WAIT-TO-START light illuminates, turn ignition off. Remove jumper wire and go to next step. If WAIT-TO-START light does not illuminate, repair open in Orange/Black wire between ECM and WAIT-TO-START light.
5. Ensure ignition is off and ECM connector is still disconnected. Remove instrument cluster. See appropriate ANALOG INSTRUMENT CLUSTER article in ACCESSORIES & EQUIPMENT. Note location of connectors C1 and C2 on instrument cluster. (Scheme 33) Turn ignition on with engine off. Using 12-volt test light, check for voltage at terminal No. 2 (Dark Blue/White wire) on connector C1 for instrument cluster. (Scheme 34) If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open between ignition switch, fuse No. 17 (10-amp) and Dark Blue/White wire between fuse No. 17 in junction block and connector C1 for instrument cluster. This is the power supply circuit to the WAIT-TO-START light. Fuse No. 17 is located in junction block on end of driver's side of instrument panel, near door opening.
6. Turn ignition off. Inspect WAIT-TO-START light bulb. If light bulb is okay, go to next step. If light bulb is defective, replace light bulb.
7. Ensure ignition is off and ECM connector is still disconnected. Reinstall connectors on instrument cluster. Turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 37 (Orange/Black wire) on ECM connector. If voltage is 10 volts or less, go to next step. If voltage is more than 10 volts, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
8. Check for intermittent problem in wiring for WAIT-TO-START light between ECM, instrument cluster, fuse No. 17 and ignition switch. Repair as necessary.

Scheme 33

Scheme 34

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 5.
2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. Check that displayed DTC matches the FREEZE FRAME DTC. If DTC matches the FREEZE FRAME DTC, go to next step. If DTC does not match the FREEZE FRAME DTC, perform procedures for FREEZE FRAME DTC. Also check for additional DTCs and repair as necessary.
3. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter does not change to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to step 5. NOTE: Keep air intake heater actuation time to a minimum due to high current draw.
4. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 2 and note battery voltage. DO NOT actuate intake air heater No. 2 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 2. If battery voltage drops less than.5 volt when intake air heater No. 2 is actuated, go to next step. If battery voltage drops.5 volt or more when intake air heater No. 2 was actuated, intake air heater No. 2 is operating properly. Test is complete.
5. Turn ignition off. Disconnect ground circuit connector (Black/Tan wire) at intake air heater relay No. 2. Intake air heater relays are located on bracket near driver's side battery. (Scheme 32) Using DVOM, measure resistance between ground and ground circuit connector (Black/Tan wire) for intake air heater relay No. 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Tan wire between intake air heater relay No. 2 and ground connection. Ground connection is located at ground connection for negative battery terminal.
6. Turn ignition off. Disconnect intake air heater relay No. 2 control circuit connector (Yellow/Black wire). Intake air heater relays are located on bracket near driver's side battery. (Scheme 32) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between ground terminal No. 47 (Orange/Black wire) on ECM connector. see scheme 12 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Orange/Black wire between ECM and intake air heater relay No. 2.
7. Reinstall ground circuit connector (Black/Tan wire) at intake air heater relay No. 2. Ensure intake air heater relay No. 2 control circuit connector (Orange/Black wire) is disconnected at intake air heater relay No. 2. Connect one end of jumper wire to intake air heater relay No. 2 control circuit connector (Orange/Black wire) terminal on intake air heater relay No. 2. Momentarily touch other end of jumper wire to battery voltage while listening for operating sound (click) at intake air heater relay No. 2. If operating sound is heard at intake air heater relay No. 2, remove jumper wire and go to next step. If operating sound is not heard at intake air heater relay No. 2, remove jumper wire. Replace intake air heater relay No. 2.
8. Ensure intake air heater relay No. 2 control circuit connector (Orange/Black wire) is disconnected at intake air heater relay No. 2 and ECM connector is still disconnected. Using DVOM, measure resistance between intake air heater relay No. 2 control circuit connector (Orange/Black wire) at intake air heater relay No. 2 and terminal No. 47 (Orange/Black wire) on ECM connector. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Orange/Black wire between intake air heater relay No. 2 and ECM.

Note. Fuel pump relay DTC may set by removing fuel pump relay and starting engine. DTC must be cleared after repairs.

Turn ignition off. Remove fuel pump relay from Power Distribution Center (PDC). see scheme 30 Start vehicle and allow to run until the engine stalls. Attempt to restart engine until it will no longer start. This will relieve fuel pressure. Turn ignition off. Remove fuel tank. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. Remove fuel pump module from fuel tank. Inspect inside of fuel tank for damage or obstructions which would cause problems with operation of fuel level sensor. If fuel tank is not damaged or obstructed, replace fuel level sensor. If fuel tank is damaged or obstructed, repair or replace fuel tank as necessary.

1. Turn ignition on with engine off. Using scan tool, read fuel level sensor voltage. If fuel level sensor voltage is less than.4 volt, go to next step. If fuel level sensor voltage is.4 volt or more, go to step 5.
2. Turn ignition off. Disconnect fuel pump module connector. Fuel pump module is located on top of fuel tank and contains fuel level sensor along with fuel supply and return line fittings. (Scheme 35) Fuel pump module may also be referred to as fuel tank module. Turn ignition on with engine off. Using scan tool, read fuel level sensor voltage. If fuel level sensor voltage is 9 volts or less, go to next step. If fuel level sensor voltage is more than 9 volts, replace fuel level sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. Fuel level sensor is located on fuel pump module.
3. Turn ignition off. Ensure fuel pump module connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between terminals No. 1 (Black wire) and No. 3 (Dark Blue/White wire) on fuel pump module connector. see scheme 17 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair Black wire and Dark Blue/White wire as they are shorted together. Black wire goes from fuel level sensor to ground connection located at driver's side front corner of engine compartment, on fender inner panel, near windshield washer fluid reservoir. Dark Blue/White wire goes from fuel pump module to PCM. This is the fuel level sensor signal wire.
4. Ensure fuel pump module connector and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and No. 3 (Dark Blue/White wire) on fuel pump module connector. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, short to ground in Dark Blue/White wire between PCM and fuel pump module.
5. Ensure ignition is on with engine off. Using scan tool, monitor fuel level sensor voltage while wiggling wiring harness and connectors between fuel pump module and PCM. Fuel pump module is located on top of fuel tank and contains fuel level sending unit along with fuel supply and return line fittings. (Scheme 35) Fuel pump module may also be referred to as fuel tank module. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If fuel level sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If fuel level sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
6. Turn ignition off. Inspect wiring harness and connectors between fuel pump module and PCM. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary.

Scheme 35

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to step 7.
2. Using scan tool, check CAB module for DTCs. If no CAB module DTCs exist, go to next step. If any CAB module DTCs exist, perform test procedures for CAB module DTCs. See appropriate ANTI-LOCK article in BRAKES.
3. Ensure ignition is off. Disconnect 14-pin CAB module connector. CAB module is located near PDC at driver's side of engine compartment. (Scheme 36) On models with 4-wheel anti-lock brakes which may be referred to as EBC 325, there are 2 connectors at CAB module. Connector C1 is a 14-pin connector and connector C2 is a 4-pin connector. On models with rear wheel anti-lock brakes which may be referred to as EBC 2, there is only one 14-pin connector at CAB module. On all models, turn ignition on with engine off. Using DVOM, measure voltage between ground and terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. see scheme 10 If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage on White/Orange wire between CAB module and PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3
4. Turn ignition off. Ensure 14-pin CAB module connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between terminal No. 12 (White/Orange wire) on 14-pin CAB module connector and terminal No. 27 (White/Orange wire) on PCM connector C2. see scheme 10and see scheme 22. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in White/Orange wire between CAB module and PCM.
5. Using DVOM, measure resistance between ground and terminal No. 27 (White/Orange wire) on PCM connector C2. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in White/Orange wire between CAB module and PCM.
6. Ensure ignition is off. Reinstall PCM connectors. Ensure 14-pin CAB module connector is still disconnected. Turn ignition on with engine off. Connect one end of jumper wire to terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. Using scan tool, monitor vehicle speed sensor signal while momentarily touching other end of jumper wire to ground. If scan tool displays zero MPH, go to next step. If scan tool displays more than zero MPH, replace CAB module. See appropriate ANTI-LOCK article in BRAKES. WARNING: Keep hands and feet clear of rotating wheels when performing following test procedure.
7. DTC is being caused by an intermittent problem. Reconnect 14-pin CAB module connector. Raise and support vehicle so rear wheels are free to rotate. Start engine and allow engine to idle. Using scan tool, monitor vehicle speed sensor signal. Place transmission in any forward gear and allow wheels to rotate. If scan tool displays more than zero MPH, go to next step. If scan tool displays zero MPH, go to step 9.
8. Shut engine off. At this time, conditions required to set DTC are not present. Using scan tool, read FREEZE FRAME data to determine when DTC was stored. Attempt to duplicate conditions recorded in FREEZE FRAME data to see if DTC reoccurs. Vehicle must be road tested, as this DTC cannot be stored by operating vehicle on a hoist. Inspect wiring harness and connectors between PCM and CAB module. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary.
9. Shut engine off. Turn ignition on. Using scan tool, check CAB module for DTCs. If no CAB module DTCs exist, go to next step. If any CAB module DTCs exist, perform test procedures for CAB module DTCs. See appropriate ANTI-LOCK article in BRAKES.
10. Ensure ignition is off. Disconnect 14-pin CAB module connector. CAB module is located near PDC at driver's side of engine compartment. (Scheme 36) On models with 4-wheel anti-lock brakes which may be referred to as EBC 325, there are 2 connectors at CAB module. Connector C1 is a 14-pin connector and connector C2 is a 4-pin connector. On models with rear wheel anti-lock brakes which may be referred to as EBC 2, there is only one 14-pin connector at CAB module. On all models, turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. see scheme 10 This is the vehicle speed sensor signal circuit. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage on White/Orange wire between CAB module and PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3
11. Turn ignition off. Ensure 14-pin CAB module connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Using DVOM, measure resistance between terminal No. 12 (White/Orange wire) on 14-pin CAB module connector and terminal No. 27 (White/Orange wire) on PCM connector C2. see scheme 10and see scheme 22. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in White/Orange wire between CAB module and PCM.
12. Ensure 14-pin CAB module connector is still disconnected and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 27 (White/Orange wire) on PCM connector C2. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in White/Orange wire between CAB module and PCM.

Scheme 36

1. Turn ignition on. Using scan tool, check for wheel speed sensor codes set in CAB module. If no wheel speed sensor DTCs exist, go to next step. If any wheel speed sensor DTCs exist, perform test procedures for CAB module DTCs. See appropriate ANTI-LOCK article in BRAKES.
2. Ensure ignition is off. Disconnect 14-pin CAB module connector. CAB module is located near PDC at driver's side of engine compartment. (Scheme 36) On models with 4-wheel anti-lock brakes which may be referred to as EBC 325, there are 2 connectors at CAB module. Connector C1 is a 14-pin connector and connector C2 is a 4-pin connector. On models with rear wheel anti-lock brakes which may be referred to as EBC 2, there is only one 14-pin connector at CAB module. On all models, connect one end of jumper wire to terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. see scheme 10 Using scan tool, monitor vehicle speed sensor signal while momentarily touching other end of jumper wire to ground. If scan tool displays zero MPH, go to next step. If scan tool displays more than zero MPH, replace CAB module. See appropriate ANTI-LOCK article in BRAKES.
3. Turn ignition off. Remove jumper wire. Turn ignition on. Using DVOM, measure voltage between ground and terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. see scheme 10 If voltage is not 4-6 volts, go to next step. If voltage is 4-6 volts, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. Turn ignition off. Disconnect Engine Control Module (ECM) connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on. Ensure DVOM is connected as in previous step. If voltage is not 4-6 volts, go to next step. If voltage is 4-6 volts, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
5. Turn ignition off. Disconnect PCM connectors. see scheme 3 Turn ignition on. Ensure DVOM is connected as in previous step. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to voltage in White/Orange wire between CAB, ECM and PCM.
6. Using DVOM, measure resistance between ground and terminal No. 12 (White/Orange wire) on 14-pin CAB module connector. If resistance is 100 ohms or more, go to next step. If resistance is less than 100 ohms, repair short to ground in White/Orange wire.
7. Using DVOM, measure resistance of White/Orange wire between terminal No. 12 on 14-pin CAB module connector and terminal No. 27 on PCM connector C2. see scheme 12and see scheme 22. If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in White/Orange wire.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1488 does not exist, go to next step. If DTC P1488 exists, perform «DTC P1488: AUXILIARY 5 VOLT OUTPUT TOO LOW»(ref-97349-S39663728042001050200000) test.
2. Using scan tool, recheck for any other DTCs. If no other DTCs exist, go to next step. If any other DTCs exist, repair all existing DTCs before continuing with this test procedure.
3. Turn ignition off. Disconnect engine oil pressure sensor connector. Engine oil pressure sensor is located on driver's side of cylinder block, just behind ECM and contains 3-pin connector. (Scheme 37) Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on engine oil pressure sensor connector. see scheme 14 If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair faulty Orange wire between ECM and engine oil pressure sensor.
4. Ensure ignition is on with engine off. Using DVOM, measure voltage between terminals "A" (Orange wire) and "B" (Black/Light Blue wire) on engine oil pressure sensor connector. If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair open in Black/Light Blue wire between ECM and engine oil pressure sensor.
5. Ensure ignition is on with engine off and engine oil pressure sensor connector is still disconnected. Using scan tool, read engine oil pressure sensor voltage. Engine oil pressure sensor voltage may also be referred to as oil pressure sensor voltage. If engine oil pressure sensor voltage is.39-.61 volt, go to next step. If engine oil pressure sensor voltage is not.39-.61 volt, replace engine oil pressure sensor.
6. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal "C" (Gray/Black wire) on engine oil pressure sensor connector and terminal No. 6 (Gray/Black wire) on ECM connector. see scheme 12and see scheme 14. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Black wire between ECM and engine oil pressure sensor.
7. Ensure engine oil pressure sensor connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal "C" (Gray/Black wire) on engine oil pressure sensor connector. If resistance is 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Gray/Black wire between ECM and engine oil pressure sensor.

Scheme 37

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1475 does not exist, go to next step. If DTC P1475 is present, perform «DTC P1475: AUXILIARY 5 VOLT OUTPUT TOO HIGH»(ref-97349-S27905557912001050200000) test.
2. Using scan tool, recheck for any other DTCs. If no other DTCs exist, go to next step. If any other DTCs exist, repair all existing DTCs before continuing with this test procedure.
3. Turn ignition off. Disconnect engine oil pressure sensor connector. Engine oil pressure sensor is located on driver's side of cylinder block, just behind ECM and contains 3-pin connector. (Scheme 37) Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on engine oil pressure sensor connector. see scheme 14 If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair faulty Orange wire between ECM and engine oil pressure sensor.
4. Ensure ignition is on with engine off. Using DVOM, measure voltage between terminals "A" (Orange wire) and "B" (Black/Light Blue wire) on engine oil pressure sensor connector. If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair open in Black/Light Blue wire between ECM and engine oil pressure sensor.
5. Ensure ignition is on with engine off and engine oil pressure sensor connector is still disconnected. Using scan tool, read engine oil pressure sensor voltage. Engine oil pressure sensor voltage may also be referred to as oil pressure sensor voltage. If engine oil pressure sensor voltage is.39-.61 volt, go to next step. If engine oil pressure sensor voltage is not.39-.61 volt, replace engine oil pressure sensor.
6. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal "C" (Gray/Black wire) on engine oil pressure sensor connector and terminal No. 6 (Gray/Black wire) on ECM connector. see scheme 12and see scheme 14. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Black wire between ECM and engine oil pressure sensor.
7. Ensure engine oil pressure sensor connector and ECM connector are still disconnected. Using DVOM, measure resistance between terminals "A" (Orange wire) and "C" (Gray/Black wire) on connector for engine oil pressure sensor. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair Orange wire and Gray/Black wire between ECM and engine oil pressure sensor, as they are shorted together.
8. Turn engine on with engine off. Using scan tool, read engine oil pressure sensor voltage. Engine oil pressure sensor voltage may also be referred to as oil pressure sensor voltage. If engine oil pressure sensor voltage is.39-.61 volt, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If engine oil pressure sensor voltage is not.39-.61 volt, test is complete.

1. Ensure engine oil level is correct. Oil pressure should be checked. Disconnect engine oil pressure sensor connector. Engine oil pressure sensor is located on driver's side of cylinder block, just behind Engine Control Module (ECM) and contains 3-pin connector. (Scheme 37) Remove engine oil pressure sensor and install mechanical oil pressure gauge.
2. Start engine and allow engine to warm to normal operating temperature. Check oil pressure with engine idling and at 2000 RPM at normal operating temperature. Oil pressure should be at least 10 psi (.7 kg/cm 2 ) at idle and at least 30 psi (2.1 kg/cm 2 ) at 2000 RPM. If oil pressure is within specification, replace engine oil pressure sensor. Install and tighten engine oil pressure sensor to 12 ft. lbs. (16 N.m). If oil pressure is not within specification, repair engine mechanical problem as necessary. Install and tighten engine oil pressure sensor to 12 ft. lbs. (16 N.m).

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC: P1682 does not exist, go to next step. If DTC: P1682 exists, perform «DTC P1682: CHARGING SYSTEM VOLTAGE TOO LOW»(ref-97349-S08663943492001050200000) test.
2. Check generator belt condition and tension. Adjust or replace generator belt as necessary. Check for high resistance in battery cables. If either battery cable has a voltage drop of.2 volt or more, replace battery cable. If generator belt and battery cables are okay, go to next step.
3. Using DVOM, measure voltage between battery terminals. If voltage is 12 volts or more, go to next step. If voltage is less than 12 volts, recharge or replace battery as necessary.
4. Ensure ignition is off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using 12-volt test light, check for voltage at terminals No. 48 (Red/White wire) and No. 50 (Red/White wire) on ECM connector. see scheme 12 These are the fused B+ circuits to ECM. If test light illuminates brightly at both terminals, go to next step. If test light does not illuminate brightly at both terminals, go to step 7. NOTE: In next step, starter current draw may be higher if engine is cold, engine is new (tight) or a higher viscosity of oil than recommended is used.
5. Perform starter draw test with starter installed. Starter draw should be 450-700 amps. If starter draw is not within specification, repair or replace starter. If starter draw is within specification, using DVOM, measure voltage between battery terminals while cranking engine. If voltage is at 6.2 volts or more while cranking engine, go to next step. If voltage is less than 6.2 volts while cranking engine, recharge or replace battery.
6. Ensure ignition is off and ECM connector is still disconnected. Using 12-volt test light connected to battery voltage, check for voltage at terminals No. 30 (Black/Tan wire) and No. 49 (Black/Tan wire) on ECM connector. These are the ECM ground circuits. If test light illuminates brightly at both terminals, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If test light does not illuminate brightly at any terminal, repair open ground circuit on Black/Tan wire between ECM and ground connection. Ground connection is located at ground connection for negative battery terminal. NOTE: In next step, starter current draw may be higher if engine is cold, engine is new (tight) or a higher viscosity of oil than recommended is used.
7. Perform starter draw test with starter installed. Starter draw should be 450-700 amps. If starter draw is not within specification, repair or replace starter. If starter draw is within specification, using DVOM, measure voltage between battery terminals while cranking engine. If voltage is 6.2 volts or more while cranking engine, go to next step. If voltage is less than 6.2 volts while cranking engine, recharge or replace battery.
8. Ensure ignition is off and ECM connector is still disconnected. Remove fuse No. 3 (20-amp) from Power Distribution Center (PDC). Fuse No. 3 may also be referred to as FUSE 3 ENGINE CONT 2. see scheme 30 PDC is located at driver's side front corner of engine compartment. Using DVOM, measure resistance between Red/White wire cavity for fuse No. 3 and terminals No. 48 (Red/White wire) and No. 50 (Red/White wire) on ECM connector. This is the B+ circuit to ECM and goes from fuse No. 3 to terminal No. 7 on joint connector No. 2 and then from terminal No. 9 on joint connector No. 2 to ECM. Joint connector No. 2 is located on PDC. see scheme 30 If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Red/White wire between fuse No. 3 and ECM.
9. Ensure fuse No. 3 (20-amp) is removed from PDC. Using 12-volt test light, check for voltage at battery supply circuit (Red wire) cavity for fuse No. 3. If test light illuminates brightly, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If test light does not illuminate brightly, repair battery supply circuit (Red wire) from battery to fuse No. 3.

1. Start engine and allow engine to idle. Using DVOM and Probe (6801), backprobe terminals No. 48 (Red/White wire) and No. 50 (Red/White wire) on ECM connector. see scheme 12 ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If voltage is less than 17 volts at both terminals, go to next step. If voltage is 17 volts or more on either B+ circuit, perform CHARGING SYSTEM test under MISCELLANEOUS CONTROLS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article.
2. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1594 does not exist in Powertrain Control Module (PCM), go to next step. If DTC P1594 exists in PCM, perform «DTC P1594: CHARGING SYSTEM VOLTAGE TOO HIGH»(ref-97349-S13293684292001050200000) test.
3. Shut engine off. Turn ignition on with engine off. Using DVOM and probe, backprobe terminals No. 48 (Red/White wire) and No. 50 (Red/White wire) on ECM connector. If voltage is less than 17 volts at both terminals, go to next step. If voltage is 17 volts or more on either B+ circuit, check for correct battery installation.
4. Turn ignition off. Disconnect ECM connector. Using 12-volt test light connected to battery voltage, check for voltage at terminals No. 30 (Black/Tan wire) and No. 49 (Black/Tan wire) on ECM connector. These are the ECM ground circuits. If test light illuminates brightly at both terminals, test is complete. If test light does not illuminate brightly at any terminal, repair open or high resistance on Black/Tan wire between ECM and ground connection. Ground connection is located at ground connection for negative battery terminal.

Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0601 does not exist, test is complete. If DTC P0601 exists, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. PCM is located at passenger's side rear corner of engine compartment. see scheme 3

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, DTC is not present at this time. Using scan tool, clear DTCs.
2. At this time, conditions required for DTC to be stored are not present. Ensure ignition is on with engine off. Using scan tool, read and record FREEZE FRAME data. Road test vehicle under conditions displayed in FREEZE FRAME data parameters. Check for pertinent technical service bulletins that apply to vehicle. Update ECM calibration using required equipment. If ECM calibration is updated before reading FREEZE FRAME data, the FREEZE FRAME data will be erased. Using scan tool, check for DTCs. If DTC P0602 does not return, test is complete. If DTC P0602 returns, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2

Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, test is complete.

Note. To identify negative (-) terminal of generator for testing purposes, use a DVOM and measure voltage at both field terminals. The positive (+) terminal will show battery voltage and the negative (-) terminal will indicate 3-8 volts less than positive (+) terminal voltage.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. Record all DTCs and FREEZE FRAME data. Clear all DTCs. Turn ignition off. Inspect PCM connectors and 2-wire connector at rear of generator for corroded, damaged or pushed-out terminals. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Clean and/or repair connectors as necessary. Turn ignition on with engine off. Using scan tool, actuate generator field driver. Using 12-volt test light, check for voltage at terminal No. 1 (Dark Green wire) on 2-wire connector at rear of generator. If test light blinks, go to next step. If test light does not blink, go to step 5.
2. Ensure ignition is on with engine off and generator field driver is still actuated by scan tool. Using 12-volt test light, check for voltage at terminal No. 2 (Dark Blue wire) on 2-wire connector at rear of generator. If test light illuminates, go to next step. If test light does not illuminate, repair open or high resistance on Dark Blue wire between generator and terminal No. 25 on PCM connector C3. see scheme 22
3. Turn ignition off. Inspect wiring harness and connectors between PCM and 2-wire connector on rear of generator. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
4. Turn ignition on with engine off. Using scan tool, actuate generator field driver. Wiggle wiring harness and connectors between PCM and 2-wire connector on rear of generator. Using scan tool, check for DTCs. If DTC P0622 does not exist, test is complete. If DTC P0622 exists, repair wiring harness or connector that caused DTC to return.
5. Ensure ignition is on with engine off and generator field driver is still actuated by scan tool. Using 12-volt test light, check for voltage at terminal No. 2 (Dark Blue wire) on 2-wire connector at rear of generator. If test light illuminates, go to next step. If test light does not illuminate, repair open or high resistance on Dark Blue wire between generator and terminal No. 25 on PCM connector C3. see scheme 22 NOTE: In next step when disconnecting battery terminals, disconnect negative battery terminal first. When reconnecting battery terminals, connect positive battery terminal first.
6. Stop actuation of generator field driver. Turn ignition off. Disconnect battery terminals. Disconnect 2-wire connector at rear of generator. Disconnect PCM connectors. Using DVOM, measure resistance between both generator field driver terminals on back of generator. These are the terminals that 2-wire connector fits on at rear of the generator. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair or replace generator as necessary.
7. Ensure ignition is off. Using DVOM, measure resistance between terminal No. 10 (Dark Green wire) on PCM connector C2 and terminal No. 1 (Dark Green wire) on 2-wire connector at rear of generator. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green wire between PCM and generator.
8. Using DVOM, measure resistance between ground and terminal No. 1 (Dark Green wire) on 2-wire connector at rear of generator. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Dark Green wire between PCM and generator.

1. Turn ignition on with engine off. Using scan tool, actuate A/C clutch relay. Listen for clicking sound at A/C clutch relay. The A/C clutch relay is located in Power Distribution Center (PDC) at driver's side front corner of engine compartment. see scheme 30 If clicking sound is heard at A/C clutch relay, go to next step. If clicking sound is not heard at A/C clutch relay, go to step 4.
2. Ensure ignition is still on and A/C clutch relay is still actuated using scan tool. Wiggle wiring harness and connectors from A/C clutch relay to PCM while A/C clutch relay is still actuated. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If clicking sound at A/C clutch relay was not interrupted while wiggling wiring harness and connectors, go to next step. If clicking sound at A/C clutch relay was interrupted while wiggling wiring harness and connectors, repair wiring or connectors as necessary.
3. Turn ignition off. Inspect PCM connectors for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between A/C clutch relay and PCM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.
4. Turn ignition off. Remove A/C clutch relay from PDC. Note which terminals on A/C clutch relay correspond with cavities in PDC. see scheme 30 Using DVOM, measure resistance between terminals on A/C clutch relay that correspond with cavities No. 85 and 86 in PDC. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace A/C clutch relay.
5. Turn ignition on with engine off. Using 12-volt test light, check for voltage at cavity No. 86 (Dark Blue/White wire) in PDC for A/C clutch relay. see scheme 30 If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open between ignition switch, fuse No. 11 (10-amp) and Dark Blue/White wire between fuse No. 11 in junction block and cavity No. 86 in PDC for A/C clutch relay. Fuse No. 11 is located in junction block on end of driver's side of instrument panel, near door opening.
6. Turn ignition off. Ensure A/C clutch relay is still removed from PDC. Disconnect PCM connectors. see scheme 3 Using DVOM, measure resistance between ground and terminal No. 1 (Dark Blue/Orange wire) on PCM connector C3. see scheme 22 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Orange wire between PCM and cavity No. 85 in PDC for A/C clutch relay.
7. Ensure A/C clutch relay is still removed from PDC. Using DVOM, measure resistance between cavity No. 85 (Dark Blue/Orange wire) in PDC for A/C clutch relay and terminal No. 1 (Dark Blue/Orange wire) on PCM connector C3. see scheme 22and see scheme 30. If resistance is less than 5 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Dark Blue/Orange wire between PCM and cavity No. 85 in PDC for A/C clutch relay.

1. Ensure ignition is off. Disconnect FPCM connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 4 (Violet/Orange wire) on FPCM connector and terminal No. 34 (Violet/Orange wire) on ECM connector. see scheme 12and see scheme 16. If resistance is less than 5 ohms on Violet/Orange wire, go to next step. If resistance is 5 ohms or more, repair open in Violet/Orange wire as necessary.
2. Ensure FPCM connector and ECM connector are still disconnected. Measure resistance between terminal No. 4 (Violet/Purple wire) and No. 6 (Black/Tan wire) at FPCM connector. Violet/Orange wire is the low idle select circuit and Black/Tan wire is the ground circuit. If resistance is 5 ohms or more, go to next step. If resistance is 5 ohms or less between the wires, repair wiring as necessary.
3. Ensure FPCM connector and ECM connector are still disconnected. Measure resistance between ground and terminal No. 4 (Violet/Purple wire) at FPCM connector. If resistance is 5 ohms or more, go to next step. If resistance is 5 ohms or less, repair as necessary.
4. Ensure ignition is off and FPCM connector is still disconnected. Reinstall ECM connector. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 4 (Violet/Orange wire) on FPCM connector. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
5. Turn ignition off. Ensure FPCM connector is still disconnected. Disconnect ECM connector. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 4 (Violet/Orange wire) on FPCM connector. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage on Violet/Orange wire between FPCM and ECM.
6. Turn ignition off. Ensure FPCM connector is still disconnected. Reinstall ECM connector. Using DVOM, check for short to ground between cylinder block and terminal No. 4 (Violet/Orange wire) on FPCM connector. If Violet/Orange wire is not shorted to ground, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If Violet/Orange wire is shorted to ground, replace ECM.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. At this time, conditions required for DTC to be stored are not present. Ensure ignition is on with engine off. Using scan tool, read and record FREEZE FRAME data. Road test vehicle under conditions displayed in FREEZE FRAME data parameters while noting DTC SPECIFIC GOOD TRIP COUNTER. If DTC SPECIFIC GOOD TRIP counter does not change to zero, test is complete. If DTC SPECIFIC GOOD TRIP counter changes to zero, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition off. Remove fuel pump relay from Power Distribution Center (PDC). see scheme 30 PDC is located at driver's side front corner of engine compartment. Fuel pump relay may also be referred to as fuel injection pump relay. Note which terminals on fuel pump relay correspond with cavities in PDC. see scheme 30 Using DVOM, measure resistance between terminals on fuel pump relay that correspond with cavities No. 30 and 87 in PDC. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, replace fuel pump relay.
2. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Disconnect Fuel Pump Control Module (FPCM) connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) Using 12-volt test light, check for voltage at terminal No. 36 (Brown/White wire) on ECM connector. see scheme 12 If test light does not illuminate, go to next step. If test light illuminates, repair short to voltage on Brown/White wire between ECM and cavity No. 86 in PDC for fuel pump relay.
3. Ensure ignition is off and fuel pump relay is removed from PDC. Ensure ECM connector and FPCM connector are still disconnected. Using 12-volt test light, check for voltage at terminal No. 7 (Red/Light Green wire) on FPCM connector. see scheme 16 If test light does not illuminate, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If test light illuminates, repair short to voltage on Red/Light Green wire between FPCM and cavity No. 87 in PDC for fuel pump relay.

1. Ensure ignition is off. Disconnect APPS connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Start engine and allow engine to idle. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. see scheme 4 If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 4.
2. Shut engine off. Ensure APPS connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, repair short to voltage on Dark Blue/White wire between APPS and ECM when engine is running.
3. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If voltage is 5.5 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is more than 5.5 volts, repair short to voltage on Dark Blue/White wire between APPS and ECM when ignition is on.
4. Turn ignition off. Using DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts or less, go to step 7.
5. Ensure APPS connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is more than 5.5 volts, go to next step. If voltage is 5.5 volts on less, repair short to voltage on Light Blue/Black wire between APPS and ECM.
6. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 3 (Light Blue/Black wire) on APPS connector. If voltage is 5.5 volts or less, replace ECM. If voltage is more than 5.5 volts, repair short to voltage on Light Blue/Black wire between APPS and ECM when ignition is on.
7. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 5 (Dark Blue/White wire) on APPS connector and terminal No. 31 (Dark Blue/White wire) on ECM connector. see scheme 4and see scheme 12. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Blue/White wire between APPS and ECM.
8. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 4 (Black/Yellow wire) on APPS connector and terminal No. 32 (Black/Yellow wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Yellow wire between APPS and ECM.
9. Ensure ignition is off. Ensure APPS connector and ECM connector are still disconnected. Measure resistance between terminal No. 3 (Light Blue/Black wire) on APPS connector and terminal No. 25 (Light Blue/Black wire) on ECM connector. If resistance is less than 5 ohms, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Light Blue/Black wire between APPS and ECM.

1. Check that charging system is operating properly. If charging system operates properly, go to next step. If charging system does not operate properly, perform CHARGING SYSTEM test under MISCELLANEOUS CONTROLS in SYSTEM & COMPONENT TESTING - RAM PICKUP - DIESEL article.
2. Ensure ignition is off. Using DVOM, measure voltage between battery terminals. If voltage is 12 volts or more, go to next step. If voltage is less than 12 volts, recharge or replace battery as necessary.
3. Perform starter draw test with starter installed. Starter draw should be 450-700 amps. If starter draw is not within specification, repair or replace starter. If starter draw is within specification, using DVOM, measure voltage between battery terminals while cranking engine. If voltage is 8 volts or more while cranking engine, go to next step. If voltage is less than 8 volts while cranking engine, recharge or replace battery.
4. Ensure ignition is off. Disconnect Fuel Pump Control Module (FPCM) connector. FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. FPCM connector is located on end of fuel injection pump. (Scheme 30) Turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 7 (Red/Light Green wire) on FPCM connector. see scheme 16 If voltage is more than 8 volts, go to next step. If voltage is 8 volts or less, perform «DTC P0215: FUEL INJECTION PUMP CONTROL CIRCUIT»(ref-97349-S42573244632001050200000) test.
5. Turn ignition off. Ensure FPCM connector is still disconnected. Using 12-volt test light connected to battery voltage, check for voltage at terminal No. 6 (Black/Tan wire) on FPCM connector. This is the ground circuit for FPCM. If test light illuminates brightly, test is complete. If test light does not illuminate brightly, repair open or high resistance on Black/Tan wire between FPCM and ground connection. Ground connection is located at ground connection for negative battery terminal.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to step 5. NOTE: Keep air intake heater actuation time to a minimum due to high current draw.
2. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 1 and note battery voltage. DO NOT actuate intake air heater No. 1 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 1. If battery voltage drops more than.5 volt when intake air heater No. 1 is actuated, go to next step. If battery voltage drops.5 volt or less when intake air heater No. 1 is actuated, go to step 13.
3. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 2 and note battery voltage. DO NOT actuate intake air heater No. 2 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 2. If battery voltage drops more than.5 volt when intake air heater No. 2 is actuated, go to next step. If battery voltage drops.5 volt or less when intake air heater No. 2 is actuated, go to step 10.
4. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to step 9. If DTC SPECIFIC GOOD TRIP counter does not change to zero, conditions required for DTC to be stored are not present at this time. Test is complete.
5. Ensure ignition is on with engine off. Using scan tool, check for DTCs. Check that displayed DTC matches the FREEZE FRAME DTC. If DTCs displayed are the same, go to next step. If DTCs displayed are not the same, perform procedures for FREEZE FRAME DTC. Also check for additional DTCs and repair as necessary.
6. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, conditions required for DTC to be stored are not present at this time. Test is complete. NOTE: Keep air intake heater actuation time to a minimum due to high current draw.
7. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 1 and note battery voltage. DO NOT actuate intake air heater No. 1 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 1. If battery voltage drops more than.5 volt when intake air heater No. 1 is actuated, go to next step. If battery voltage drops.5 volt or less when intake air heater No. 1 is actuated, go to step 13.
8. Ensure ignition is on with engine off. Using DVOM, check and record voltage at positive battery terminal. While monitoring battery voltage, using scan tool, briefly actuate intake air heater No. 2 and note battery voltage. DO NOT actuate intake air heater No. 2 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 2. If battery voltage drops more than.5 volt when intake air heater No. 2 is actuated, go to next step. If battery voltage drops.5 volt or less when intake air heater No. 2 is actuated, go to step 10.
9. Problem is intermittent. Turn ignition off. Inspect Engine Control Module (ECM) connectors for corroded, pushed out or damaged terminals. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Inspect wiring harness and connectors between ECM and intake air heater relays for chafed, pierced or partially broken wires. Inspect battery cables between batteries and intake air heater relays, and cables between intake air heater relays and intake air heater assembly. Intake air heater relays are located on bracket near driver's side battery. (Scheme 32) Intake air heater assembly is located on top of intake manifold. (Scheme 38) If terminals are not corroded, pushed out or damaged and wiring and cables are okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring or cables are damaged, repair as necessary.
10. Ensure ignition is on with engine off. Check battery cable that goes from battery to intake air heater relay No. 2 for excessive resistance by checking voltage drop on battery cable. Intake air heater relay No. 2 is located on bracket near driver's side battery. (Scheme 32) If voltage drop on battery cable is not more than.1 volt, go to next step. If voltage drop on battery cable is more than.1 volt, replace battery cable.
11. Ensure ignition is on with engine off. Check cable that goes from intake air heater relay No. 2 to intake air heater No. 2 for excessive resistance by checking voltage drop on the cable. Intake air heaters No. 1 and 2 are incorporated into intake air heater assembly located on top of intake manifold. (Scheme 38) Intake air heaters may also be referred to as intake manifold air heaters. If voltage drop on cable is not more than.1 volt, go to next step. If voltage drop on cable is more than.1 volt, replace cable.
12. Ensure ignition is on with engine off. Using DVOM, measure voltage at output terminal on intake air heater relay No. 2. This is the terminal that the cable is attached to that goes to intake air heater No. 2. If voltage is more than 12 volts, intake air heater No. 2 is defective. Replace intake air heater assembly. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is 12 volts or less, replace intake air heater relay No. 2.
13. Ensure ignition is on with engine off. Check battery cable that goes from battery to intake air heater relay No. 1 for excessive resistance by checking voltage drop on battery cable. Intake air heater relay No. 1 is located on bracket near driver's side battery. (Scheme 32) If voltage drop on battery cable is not more than.1 volt, go to next step. If voltage drop on battery cable is more than.1 volt, replace battery cable.
14. Ensure ignition is on with engine off. Check cable that goes from intake air heater relay No. 1 to intake air heater No. 1 for excessive resistance by checking voltage drop on the cable. Intake air heaters No. 1 and 2 are incorporated into intake air heater assembly located on top of intake manifold. (Scheme 38) Intake air heaters may also be referred to as intake manifold air heaters. If voltage drop on cable is not more than.1 volt, go to next step. If voltage drop on cable is more than.1 volt, replace cable.
15. Ensure ignition is on with engine off. Using DVOM, measure voltage at output terminal on intake air heater relay No. 1. This is the terminal that cable is attached to that goes to intake air heater No. 1. If voltage is more than 12 volts, intake air heater No. 1 is defective. Replace intake air heater assembly. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is 12 volts or less, replace intake air heater relay No. 1.

Scheme 38

1. Ensure ignition is off. Disconnect APPS connector. APPS is located on bracket, just above fuel injection pump. (Scheme 26) Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. see scheme 4 If voltage is 4.5 volts or less, go to next step. If voltage is more than 4.5 volts, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Turn ignition off. Ensure APPS connector is still disconnected. Measure resistance between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. This is the APPS sensor supply wire and goes from terminal No. 5 on APPS connector to terminal No. 31 on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 5.
3. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/White wire between ECM and APPS.
4. Measure resistance between terminal No. 5 (Dark Blue/White wire) and terminal No. 11 (Black/Light Blue wire) on APPS connector. The Black/Light Blue wire is the sensor ground circuit. If resistance is 5 ohms or less, repair short between Dark Blue/White and Black/Light Blue wires. If resistance is greater than 5 ohms, replace ECM.
5. Ensure APPS connector is still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block and terminal No. 5 (Dark Blue/White wire) on APPS connector. If voltage is 4.5 volts or less, go to next step. If voltage is more than 4.5 volts, replace APPS. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Measure resistance between terminal No. 5 (Dark Blue/White wire) on APPS connector and terminal No. 31 (Dark Blue/White wire) on ECM connector. see scheme 4and see scheme 12. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Dark Blue/White wire between APPS and ECM.

1. Turn ignition on with engine off. Using scan tool, actuate ASD relay. Listen for clicking sound at ASD relay. The ASD relay is located in Power Distribution Center (PDC) at driver's side front corner of engine compartment. see scheme 30 If clicking sound is heard at ASD relay, go to next step. If clicking sound is not heard at ASD relay, go to step 4.
2. Stop actuation of ASD relay. Inspect wiring harness and connectors between ASD relay and PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
3. Start engine and allow engine to idle. Wiggle wiring harness and connectors between ASD relay and PCM. If engine does not stall while wiggling wiring harness and connectors, test is complete. If engine stalls while wiggling wiring harness and connectors, repair wiring or connectors as necessary that cause engine to stall.
4. Turn ignition off. Remove ASD relay from PDC. Note cavities in PDC for ASD relay. see scheme 30 Turn ignition on with engine off. Using DVOM, measure voltage at cavity No. 86 (Light Green/Black wire) in PDC for ASD relay. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open between ignition switch, fuse No. 9 (10-amp) and Light Green/Black wire between fuse No. 9 and cavity No. 86 in PDC for ASD relay. Fuse No. 9 is located in junction block on end of driver's side of instrument panel, near door opening.
5. Note which terminals on ASD relay correspond with cavities in PDC. see scheme 30 Using DVOM, measure resistance between terminals on ASD relay that correspond with cavities No. 85 and 86 in PDC. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace ASD relay.
6. Ensure ignition is off and ASD relay is still removed from PDC. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between cavity No. 85 (Dark Blue/Yellow wire) in PDC for ASD relay and terminal No. 3 (Dark Blue/Yellow wire) on PCM connector C3. see scheme 22and see scheme 30. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Blue/Yellow wire between PCM and cavity No. 85 in PDC for ASD relay.
7. Ensure ASD relay is still removed from PDC and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 3 (Dark Blue/Yellow wire) on PCM connector C3. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Yellow wire between PCM and cavity No. 85 in PDC for ASD relay.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 4.
2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. Check that displayed DTC matches the FREEZE FRAME DTC. If DTCs displayed are the same, go to next step. If DTCs displayed are not the same, perform procedures for FREEZE FRAME DTC. Also check for additional DTCs and repair as necessary.
3. Using scan tool, check for DTCs and record FREEZE FRAME data. Try to duplicate conditions recorded in FREEZE FRAME data. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, go to step 7.
4. Turn ignition off. Remove ASD relay from Power Distribution Center (PDC). see scheme 30 PDC is located at driver's side front corner of engine compartment. see scheme 3 Note cavities in PDC for ASD relay. Using DVOM, measure voltage at cavity No. 30 (Red/Light Blue wire) in PDC for ASD relay. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open between battery, fuse No. 6 (30-amp) and Red/Light Blue wire between fuse No. 6 in PDC and cavity No. 30 in PDC for ASD relay.
5. Ensure ignition is off and ASD relay is still removed from PDC. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between cavity No. 87 (Dark Green/Orange wire) in PDC for ASD relay and terminal No. 12 (Dark Green/Orange wire) on PCM connector C3. see scheme 22and see scheme 30. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green/Orange wire between PCM and cavity No. 87 in PDC for ASD relay.
6. Ensure ignition is off. Install a substitute ASD relay. Using scan tool, clear DTCs. Start engine and allow engine to idle. Using scan tool, check for DTCs. If DTC P1389 exists, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If DTC P1389 does not exist, replace original ASD relay.
7. Using scan tool, clear DTCs. Start engine and allow engine to idle. Wiggle wiring harness and connectors between ASD relay and PCM. The ASD relay is located in Power Distribution Center (PDC) at driver's side front corner of engine compartment. see scheme 30 PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using scan tool, check for DTCs. If DTC P1389 does not exist, go to next step. If DTC P1389 exists, repair wiring harness or connectors between ASD relay and PCM that caused DTC.
8. Shut engine off. At this time, conditions required for DTC to be stored are not present. Inspect wiring harness and connectors between ASD relay and PCM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
9. Problem is intermittent. Inspect PCM connectors for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between ASD relay and PCM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 3.
2. Ensure ignition is on with engine off. At this time, DTC is intermittent. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. If DTCs displayed are not the same, repair DTC displayed with FREEZE FRAME data. If DTCs displayed are the same, try to duplicate conditions recorded in FREEZE FRAME data. Start engine and allow engine to idle. Using scan tool, read Manifold Air Pressure (MAP) sensor voltage. If MAP sensor voltage is more than 5.2 volts, shut engine off. Go to next step. If MAP sensor voltage is 5.2 volts or less, go to step 4.
3. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 Start engine and allow engine to idle. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector. see scheme 20 If voltage is 5.2 volts or less, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is more than 5.2 volts, repair short to voltage on Orange wire between MAP sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2
4. Shut engine off. Turn ignition on with engine off. Using scan tool, monitor MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling harness and connectors, repair wiring or connectors as necessary.
5. At this time, conditions required for DTC to be stored are not present. Inspect wiring harness and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
6. Problem is intermittent. Inspect MAP sensor connector and ECM connector for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between MAP sensor and ECM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to step 8.
2. Turn ignition off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector. see scheme 20 If voltage is 4.5 volts or less, go to next step. If voltage is more than 4.5 volts, replace MAP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
3. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using DVOM, measure and record voltage at terminal "A" (Orange wire) on MAP sensor connector. Turn ignition off. Disconnect CMP sensor connector. CMP sensor is located on rear of timing gear cover, directly below bottom of fuel injection pump. (Scheme 31) Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector with CMP sensor connector disconnected. If voltage is still 4.5 volts or less, go to next step. If voltage is now more than 4.5 volts, replace CMP sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using DVOM, measure and record voltage at terminal "A" (Orange wire) on MAP sensor connector. Turn ignition off. Disconnect engine oil pressure sensor connector. Engine oil pressure sensor is located on driver's side of cylinder block, just behind Engine Control Module (ECM) and contains 3-pin connector. (Scheme 37) Engine oil pressure sensor may also be referred to as oil pressure sensor. Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector with engine oil pressure sensor connector disconnected. If voltage is still 4.5 volts or less, go to next step. If voltage is now more than 4.5 volts, replace engine oil pressure sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
5. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using DVOM, measure and record voltage at terminal "A" (Orange wire) on MAP sensor connector. Turn ignition off. Disconnect WIF sensor connector. WIF sensor is located at bottom of fuel filter/water separator on driver's side of engine, just behind fuel injection pump. (Scheme 28) Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector with WIF sensor connector disconnected. If voltage is still 4.5 volts or less, go to next step. If voltage is now more than 4.5 volts, replace WIF sensor. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
6. Turn ignition off. Disconnect ECM connector. Using DVOM, measure resistance between ground and terminal No. 10 (Orange wire) on ECM connector. see scheme 12 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Orange wire between ECM, MAP sensor, engine oil pressure sensor, WIF sensor and CMP sensor.
7. Ensure ECM connector and MAP sensor connector are still disconnected. Using DVOM, measure resistance between terminal "A" (Orange wire) on MAP sensor connector and terminal No. 10 (Orange wire) on ECM connector. see scheme 12and see scheme 20. If resistance is less than 5 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Orange wire between MAP sensor and ECM.
8. Ensure ignition is on with engine off. Using scan tool, monitor MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head. see scheme 33 ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling harness and connectors, repair wiring or connectors as necessary.
9. Inspect wiring harness and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
10. Problem is intermittent. Inspect MAP sensor connector and ECM connector for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between MAP sensor and ECM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, read Battery Temperature Sensor (BTS) voltage. If BTS voltage is more than 4.5 volts, go to next step. If BTS voltage is 4.5 volts or less, go to step 6.
2. Turn ignition off. Disconnect BTS connector. BTS is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. Connect jumper wire between engine ground and terminal No. 2 (Pink/Yellow wire) on BTS connector. see scheme 5 Turn ignition on with engine off. Using scan tool, read BTS voltage. If BTS voltage is one volt or more, go to next step. If BTS voltage is less than one volt, repair open in Black/Light Blue wire between BTS, joint connector No. 1 and PCM. This is the ground circuit for BTS. Joint connector No. 1 is located in PDC at driver's side front corner of engine compartment. see scheme 30 PCM is located at passenger's side rear corner of engine compartment. see scheme 3
3. Turn ignition off. Disconnect jumper wire from engine ground and reconnect to terminal No. 1 (Black/Light Blue wire) on BTS connector. Ensure other end of jumper wire is still connected to terminal No. 2 (Pink/Yellow wire) on BTS connector. Turn ignition on with engine off. Using scan tool, read BTS voltage. If BTS voltage is one volt or more, go to next step. If BTS voltage is less than one volt, replace BTS sensor.
4. Ensure ignition is on with engine off. Using DVOM, measure voltage at terminal No. 2 (Pink/Yellow wire) on BTS connector. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage on Pink/Yellow wire between BTS and PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3
5. Turn ignition off. Ensure BTS connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Using DVOM, measure resistance between terminal No. 2 (Pink/Yellow wire) on BTS connector and terminal No. 15 (Pink/Yellow wire) on PCM connector C3. see scheme 5and see scheme 22. If resistance is less than 5 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Pink/Yellow wire between BTS and PCM.
6. Ensure ignition is on with engine off. While using scan tool to monitor BTS voltage, wiggle wiring harness and connectors between BTS and PCM. BTS is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. PCM is located at passenger's side rear corner of engine compartment. If BTS voltage does not change while wiggling wiring harness and connectors, go to next step. If BTS voltage changes while wiggling wiring harness and connectors, repair wiring or connector as necessary.
7. Turn ignition off. Inspect wiring harness and connectors between BTS and PCM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
8. Turn ignition on with engine off. At this time, DTC is intermittent. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. If DTCs displayed are not the same, repair DTC displayed with FREEZE FRAME data. If DTCs displayed are the same, try to duplicate conditions recorded in FREEZE FRAME data. Inspect BTS connector and PCM connectors for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between BTS and PCM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, read BTS voltage. If BTS voltage is less than.5 volt, go to next step. If BTS voltage is.5 volt or more, go to step 5.
2. Turn ignition off. Disconnect BTS connector. BTS is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. Turn ignition on with engine off. Using scan tool, read BTS voltage. If BTS voltage is 4 volts or less, go to next step. If BTS voltage is more than 4 volt, replace BTS.
3. Turn ignition off. Ensure BTS connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Using DVOM, measure resistance between ground and terminal No. 2 (Pink/Yellow wire) on BTS connector. see scheme 5 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Pink/Yellow wire between BTS and PCM.
4. Ensure BTS connector and PCM connectors are still disconnected. Using DVOM, measure resistance between terminals No. 1 (Black/Light Blue wire) and No. 2 (Pink/Yellow wire) on BTS connector. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair Black/Light Blue wire and Pink/Yellow wire between PCM and BTS as they are shorted together.
5. Ensure ignition is on with engine off. While using scan tool to monitor BTS voltage, wiggle wiring harness and connectors between BTS and PCM. BTS is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If BTS voltage does not change while wiggling wiring harness and connectors, go to next step. If BTS voltage changes while wiggling wiring harness and connectors, repair wiring or connector as necessary.
6. Turn ignition off. Inspect wiring harness and connectors between BTS and PCM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
7. Ensure ignition is on with engine off. At this time, DTC is intermittent. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. If DTCs displayed are not the same, repair DTC displayed with FREEZE FRAME data. If DTCs displayed are the same, try to duplicate conditions recorded in FREEZE FRAME data. Inspect BTS connector and PCM connectors for corroded, pushed out or damaged terminals. Inspect wiring harness and connectors between BTS and PCM for chafed, pierced or partially broken wires. If terminals are not corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

1. Turn ignition on with engine off. Using scan tool, actuate generator field driver. Using 12-volt test light, check for voltage at terminal No. 1 (Dark Green wire) on 2-wire connector at rear of generator. If test light blinks on and off, go to next step. If test light does not blink on and off, go to step 5.
2. Start engine and allow engine to idle. Using scan tool, read target charging voltage. If target charging voltage is more than zero volts, go to next step. If target charging voltage is zero volts, go to step 4.
3. With engine running, manually set engine speed to 1600 RPM. Using scan tool, read target charging voltage and battery voltage. Compare the 2 readings for 5 minutes. If difference between the 2 readings is more than one volt, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If voltage difference is not more than one volt, allow engine to return to idle. Shut engine off. Turn ignition on with engine off. Using scan tool, check for DTCs. Record DTCs and FREEZE FRAME data, then clear DTCs.
4. Shut engine off. Using scan tool, read temperature of BTS. Using thermometer, measure underhood temperature near battery tray. If underhood temperature is within 10 degrees of temperature of BTS temperature reading, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If underhood temperature is not within 10 degrees of temperature of BTS temperature reading, replace BTS.
5. Ensure ignition is off. Disconnect round 2-wire connector at rear of the generator. Using DVOM, measure resistance between ground and generator field driver terminal on back of generator. This is the terminal on rear of generator that Dark Green wire in the round 2-wire connector fits on. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, short exists in the generator. Repair or replace generator as necessary.
6. Ensure ignition is off and 2-wire connector at rear of generator is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Disconnect battery. Using DVOM, measure resistance between ground and terminal No. 10 (Dark Green wire) on PCM connector C2. see scheme 22 If resistance is 5 ohms or more, replace PCM. see scheme 3 If resistance is less than 5 ohms, repair short to ground in Dark Green wire between generator and PCM.

1. Turn ignition on with engine off. Using scan tool, actuate speed control vent solenoid and listen for operating sound (click) at speed control servo. Speed control servo is located below driver's side battery tray. (Scheme 39) If operating sound is heard at speed control servo, go to next step. If operating sound is not heard at speed control servo, go to step 6.
2. Ensure ignition is on and speed control vent solenoid is still actuated. Wiggle wiring harness and connectors between speed control servo, brake switch and PCM while checking for interruption of speed control vent solenoid actuation. Brake switch is located near top of brake pedal. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If speed control vent solenoid actuation was not interrupted while wiggling wiring harness and connectors, stop actuation of speed control vent solenoid. Go to next step. If speed control vent solenoid actuation was interrupted while wiggling wiring harness and connectors, stop actuation of speed control vent solenoid. Repair wiring or connectors as necessary.
3. Ensure ignition is on with engine off. Using scan tool, actuate speed control vacuum solenoid and listen for operating sound (click) at speed control servo. If operating sound is heard at speed control servo, go to next step. If operating sound is not heard at speed control servo, go to step 6.
4. Ensure ignition is on and speed control vacuum solenoid is still actuated. Wiggle wiring harness and connectors between speed control servo, brake switch and PCM while checking for interruption of speed control vacuum solenoid actuation. If speed control vacuum solenoid actuation was not interrupted while wiggling wiring harness and connectors, stop actuation of speed control vacuum solenoid. Go to next step. If speed control vacuum solenoid actuation was interrupted while wiggling wiring harness and connectors, stop actuation of speed control vacuum solenoid. Repair wiring or connectors as necessary.
5. Turn ignition off. Inspect wiring harness and connectors between speed control servo, brake switch and PCM. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary.
6. Turn ignition off. Disconnect speed control servo connector. Turn ignition on with engine off. Using scan tool, actuate speed control vent or speed control vacuum solenoid. Using 12-volt test light, check for voltage at terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. see scheme 23 DO NOT depress brake pedal when checking voltage. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, go to step 12.
7. Turn ignition off. Ensure speed control servo connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 4 (Black wire) on speed control servo connector. If resistance less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between speed control servo and ground connection. Ground connection is located at front of driver's side fender.
8. Ensure ignition is off and speed control servo connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between ground and terminal No. 1 (Tan/Red wire) on speed control servo connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Tan/Red wire between speed control servo and PCM.
9. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 2 (Light Green/Red wire) on speed control servo connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Light Green/Red wire between speed control servo and PCM.
10. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between terminal No. 1 (Tan/Red wire) on speed control servo connector and terminal No. 4 (Tan/Red wire) on PCM connector C3. see scheme 22and see scheme 23. If resistance is less than 5 ohms, go to next step. If resistance 5 ohms or more, repair open in Tan/Red wire between speed control servo and PCM.
11. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between terminal No. 2 (Light Green/Red wire) on speed control servo connector and terminal No. 5 (Light Green/Red wire) on PCM connector C3. If resistance is less than 5 ohms, replace speed control servo. See appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT. If resistance 5 ohms or more, repair open in Light Green/Red wire between speed control servo and PCM.
12. Turn ignition off. Ensure speed control servo connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. see scheme 23 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Red wire between speed control servo and brake switch. Brake switch is located near top of brake pedal.
13. Disconnect brake switch connector. Turn ignition on with engine off. Using scan tool, actuate speed control vent solenoid or speed control vacuum solenoid. Using 12-volt test light, check for voltage at terminal No. 3 (Yellow/Red wire) on brake switch connector. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, go to step 16.
14. Brake switch adjustment should be checked. Reinstall brake switch connector. To check brake switch adjustment, depress brake pedal. Ensure brakelights come on. Release brake pedal. Ensure brakelights go off. If brake switch is properly adjusted and brakelight operation is as specified, go to next step. If brakelight operation is not as specified, replace brake switch, as brake switch is nonadjustable and can only be adjusted when NEW brake switch is installed. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
15. Disconnect brake switch connector. Ensure speed control servo connector is still disconnected. Using DVOM, measure resistance between terminal No. 4 (Dark Blue/Red wire) on brake switch connector and terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. If resistance is less than 5 ohms, replace brake switch. If resistance is 5 ohms or more, repair open in Dark Blue/Red wire between brake switch and speed control servo.
16. Ensure ignition is off and brake switch connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between terminal No. 3 (Yellow/Red wire) on brake switch connector and terminal No. 11 (Yellow/Red wire) on PCM connector C3. see scheme 6and see scheme 22. If resistance is less than 5 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 5 ohms or more, repair open in Yellow/Red wire between brake switch and PCM.

Scheme 39

1. Start engine and allow engine to idle. Using scan tool in INPUTS/OUTPUTS mode, read speed control inputs. Monitor display on scan tool while turning speed control on/off switch on the steering wheel to ON and OFF positions several times with the switch returned to the ON position. If scan tool display agrees with speed control on/off switch positions, go to next step. If scan tool display does not agree with speed control on/off switch positions, go to step 3.
2. At this time, conditions required for DTC to be stored are not present. Ensure engine is idling. Using scan tool, monitor speed control on/off switch voltage while wiggling wiring harness and connectors between speed control on/off switch and PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If voltage is not more than 4.9 volts at any time while wiggling wiring harness and connectors, test is complete. If voltage is more than 4.9 volts at any time while wiggling wiring harness and connectors, repair wiring or connector as necessary that caused the voltage to fluctuate.
3. Shut engine off. Ensure ignition is off. Remove CRUISE ON/OFF switch from steering wheel. See appropriate CRUISE CONTROL SYSTEMS article. DO NOT disconnect any other connectors except the 2-pin connector. Using DVOM, measure resistance between ground and terminal No. 1 (White wire) on CRUISE ON/OFF switch connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open ground circuit on White wire. The White wire goes from CRUISE ON/OFF switch, through clockspring and then changes to Black/Light Blue wire at clockspring and goes to terminal No. 4 on PCM connector C1. see scheme 22 Clockspring is located on steering column, just below steering wheel. (Scheme 40) PCM is located at passenger's side rear corner of engine compartment. see scheme 3
4. Ensure CRUISE ON/OFF switch connector is still disconnected. Start engine and allow engine to idle. Using DVOM, measure voltage at terminal No. 2 (Dark Green/Red wire) on CRUISE ON/OFF switch connector. If voltage is less than 6 volts, go to next step. If voltage is more than 6 volts, repair short to voltage on Dark Green/Red wire. The Dark Green/Red wire goes from CRUISE ON/OFF switch, through clockspring and then changes to Red/Light Green wire at clockspring and goes to terminal No. 32 on PCM connector C3. Clockspring is located on steering column, just below steering wheel.
5. Shut engine off. Ensure ignition is off and CRUISE ON/OFF switch connector is still disconnected. Disconnect PCM connectors. Using DVOM, measure resistance between terminal No. 32 (Red/Light Green wire) on PCM connector C3 and terminal No. 2 (Dark Green/Red wire) on CRUISE ON/OFF switch connector. The Dark Green/Red wire goes from CRUISE ON/OFF switch, through clockspring and then changes to Red/Light Green wire at clockspring and goes to terminal No. 32 on PCM connector C3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 7.
6. Using DVOM, measure resistance between terminals on speed control on/off switch. If resistance is 20,300-20,700 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is not 20,300-20,700 ohms, replace CRUISE ON/OFF switch.
7. Ensure ignition off and PCM connectors are still disconnected. Disconnect clockspring connector C1. (Scheme 40) Using DVOM, measure resistance between terminal No. 1 (Red/Light Green wire) on clockspring connector C1 and terminal No. 32 (Red/Light Green wire) on PCM connector C3. see scheme 8and see scheme 22. If resistance is less than 5 ohms, replace clockspring. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If resistance is 5 ohms or more, repair open in Red/Light Green wire between clockspring and PCM.

Scheme 40

1. Start engine and allow engine to idle. Using scan tool in SENSORS mode, read speed control switch voltage. Speed control switch voltage may also be referred to as S/C switch voltage. If speed control switch voltage is less than one volt, go to next step. If speed control switch voltage is one volt or more, conditions required for DTC to be set are not present at this time. Test is complete.
2. Shut engine off. Ensure ignition is off. Remove CRUISE ON/OFF switch from steering wheel. See appropriate CRUISE CONTROL SYSTEMS article. Start engine and allow engine to idle. Using scan tool in SENSORS mode, read speed control switch voltage. If speed control switch voltage does not change to 5 volts, go to next step. If speed control switch voltage changes to 5 volts, replace CRUISE ON/OFF switch.
3. Shut engine off. Ensure ignition is off. Remove ACCEL/RESUME switch from steering wheel. Start engine and allow engine to idle. Using scan tool in SENSORS mode, read speed control switch voltage. If speed control switch voltage does not change to 5 volts, go to next step. If speed control switch voltage changes to 5 volts, replace ACCEL/RESUME switch.
4. Shut engine off. Ensure ignition is off and connectors are still disconnected at CRUISE ON/OFF and ACCEL/RESUME switches. Using DVOM, measure resistance between terminals No. 1 (White wire) and No. 2 (Dark Green/Red wires) on CRUISE ON/OFF connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair White and Dark Green/Red wires to CRUISE ON/OFF and ACCEL/RESUME switches as they are shorted together. These wires go from CRUISE ON/OFF and ACCEL/RESUME switches, through clockspring and to PCM. PCM is located at passenger's side rear corner of engine compartment. see scheme 3
5. Ensure connectors are still disconnected at CRUISE ON/OFF and ACCEL/RESUME switches. Disconnect clockspring connector C1. (Scheme 40) Using DVOM, measure resistance between ground and terminal No. 1 (Red/Light Green wire) on clockspring connector C1. see scheme 8 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Red/Light Green wire.
6. Reconnect clockspring connector. Disconnect PCM connectors. see scheme 3 Using DVOM, measure resistance between ground and terminal No. 2 (Dark Green/Red wire) on CRUISE ON/OFF or ACCEL/RESUME switch. The Dark Green/Red wire goes from CRUISE ON/OFF and ACCEL/RESUME switches, through clockspring and then changes to Red/Light Green wire at clockspring and goes to terminal No. 32 on PCM connector C3. If resistance is less than 5 ohms, replace clockspring. If resistance is 5 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Ensure battery is fully charged and generator drive belt is in good condition and properly adjusted before proceeding. Start engine and allow engine to idle. Using scan tool, read target charging voltage. If target charging voltage is more than 15.1 volts, go to next step. If target charging voltage is 15.1 volts or less, go to step 9.
2. Ensure engine is idling and at normal operating temperature. Using scan tool, read temperature of BTS. Using thermometer, measure underhood temperature near battery tray. If underhood temperature is not within 10°F of BTS, go to next step. If underhood temperature is within 10°F of BTS, go to step 9.
3. Shut engine off. Ensure ignition is off. Disconnect BTS connector. BTS is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. Connect jumper wire between terminals on BTS connector. Turn ignition on with engine off. Using scan tool, read BTS voltage. If BTS voltage is more than zero volts, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 If BTS voltage is zero volts, replace BTS.
4. Ensure ignition is on. Record all DTCs and FREEZE FRAME DATA. Using scan tool, erase DTCs. Check connectors at generator and PCM for damage. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using scan tool, actuate generator field driver circuit. Using DVOM, backprobe and measure voltage at Dark Green wire terminal No. 1 of round 2-wire connector at rear of generator. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in Dark Green wire between generator and PCM connector C2 terminal No. 10. see scheme 22
5. Turn ignition off. Disconnect PCM connectors. Disconnect round 2-wire connector at rear of generator. Using DVOM, measure resistance of Dark Green wire between generator round 2-wire connector and PCM connector C2 terminal No. 10. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Dark Green wire.
6. Using DVOM, measure resistance between ground and PCM connector C3 terminal No. 25 (Dark Blue wire). If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, repair short on ground on Dark Blue wire.
7. Using DVOM, measure resistance between ground and PCM connector C3 terminal No. 10 (Dark Green wire). If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, repair short on ground on Dark Green wire.
8. Ensure ignition is off. Connect DVOM between case of generator and negative battery post. Start engine and warm engine to normal operating temperature. Note voltage reading. If voltage is.1 volt or less, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If voltage is more than.1 volt, repair generator for high resistance between generator case (ground) and negative battery post.
9. Shut engine off. Ensure ignition is off. Connect DVOM between positive battery post and positive battery terminal on rear of the generator. Start engine and warm engine to normal operating temperature. Note voltage reading. If voltage is.4 volt or less, go to next step. If voltage is more than.4 volt, repair high resistance on Black wire and Red wire between generator and positive battery post.
10. Ensure ignition is off. Connect DVOM between case of generator and negative battery terminal. Start engine and warm engine to normal operating temperature. Note voltage reading. If voltage is.1 volt or less, go to next step. If voltage is more than.1 volt, repair generator for high resistance between generator case (ground) and negative battery terminal.
11. Ensure engine is idling and at normal operating temperature. Turn on all accessories. Adjust engine speed to 1600 RPM. Using scan tool, read target charging voltage and charging voltage. Compare the 2 readings. If difference between the 2 readings is more than one volt, go to next step. If difference between the 2 readings is one volt or less, test is complete.
12. Turn ignition on with engine off. Using scan tool, actuate generator field driver. Using DVOM, backprobe and measure voltage at each terminal in 2-wire connector at rear of generator. If voltage is less than 3 volts at either terminal, go to next step. If voltage is 3 volts or more at both terminals, charging system is operating properly at this time.
13. Ensure ignition is on. Record all DTCs and FREEZE FRAME DATA. Using scan tool, erase DTCs. Check connectors at generator Using scan tool, actuate generator field driver circuit. Using DVOM, backprobe and measure voltage at Dark Green wire terminal No. 1 of round 2-wire connector at rear of generator. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in Dark Green wire between generator and PCM connector C2 terminal No. 10. see scheme 22
14. Turn ignition off. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Disconnect round 2-wire connector at rear of the generator. Using DVOM, measure resistance between ground and terminal No. 25 (Dark Blue wire) on PCM connector C2. see scheme 22 If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue wire between PCM and round 2-wire connector for the generator.
15. Ensure PCM connectors and round 2-wire connector at rear of generator are still disconnected. Using DVOM, measure resistance between terminal No. 2 (Dark Blue wire) on round 2-wire connector for the generator and terminal No. 25 (Dark Blue wire) on PCM connector C2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Blue wire between PCM and round 2-wire connector for the generator.
16. Ensure PCM connectors and round 2-wire connector at rear of generator are still disconnected. Using DVOM, measure resistance between ground and terminal No. 10 (Dark Green wire) on PCM connector C3. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Green wire between PCM and round 2-wire connector for the generator.

1. Ensure ignition is off. Disconnect speed control servo connector. Speed control servo is located below driver's side battery tray. (Scheme 39) Turn ignition on with engine off. Using scan tool, actuate speed control servo. Using 12-volt test light, check for voltage at terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. see scheme 23 DO NOT depress brake pedal when checking for voltage. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, go to step 7.
2. Turn ignition off. Ensure speed control servo connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 4 (Black wire) on speed control servo connector. DO NOT depress brake pedal when checking resistance. If resistance less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between speed control servo and ground connection. Ground connection is located on driver's side fender panel, just below speed control servo.
3. Ensure ignition is off and speed control servo connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Using DVOM, measure resistance between terminal No. 1 (Tan/Red wire) on speed control servo connector and terminal No. 4 (Tan/Red wire) on PCM connector C3. see scheme 22and see scheme 23. If resistance is less than 5 ohms, go to next step. If resistance 5 ohms or more, repair open in Tan/Red wire between speed control servo and PCM.
4. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Tan/Red wire) on speed control servo connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Tan/Red wire between speed control servo and PCM.
5. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between terminal No. 2 (Light Green/Red wire) on speed control servo connector and terminal No. 5 (Light Green/Red wire) on PCM connector C3. If resistance is less than 5 ohms, go to next step. If resistance 5 ohms or more, repair open in Light Green/Red wire between speed control servo and PCM.
6. Ensure speed control servo connector and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 2 (Light Green/Red wire) on speed control servo connector. If resistance is 5 ohms or more, replace speed control servo. If resistance is less than 5 ohms, repair short to ground in Light Green/Red wire between speed control servo and PCM.
7. Turn ignition off. Disconnect brake switch connector. Start engine and allow engine to idle. Place speed control switch in ON position. Shut engine off. Turn ignition on with engine off. Using scan tool, actuate speed control servo. Using 12-volt test light, check for voltage at terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. DO NOT depress brake pedal when checking for voltage. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, go to step 11.
8. Brake switch adjustment should be checked. Reinstall brake switch connector. To check brake switch adjustment, depress brake pedal. Ensure brakelights come on. Release brake pedal. Ensure brakelights go off. If brake switch is properly adjusted and brakelight operation is as specified, go to next step. If brakelight operation is not as specified, replace brake switch, as brake switch is nonadjustable and can only be adjusted when NEW brake switch is installed. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
9. Ensure ignition is off and speed control servo connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. If resistance 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Red wire between speed control servo and brake switch.
10. Disconnect brake switch connector. Using DVOM, measure resistance between terminal No. 4 (Dark Blue/Red wire) on brake switch connector and terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. see scheme 6and see scheme 23. If resistance is less than 5 ohms, replace brake switch. If resistance 5 ohms or more, repair open in Dark Blue/Red wire between brake switch and speed control servo.
11. Ensure ignition is off and speed control servo connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 3 (Dark Blue/Red wire) on speed control servo connector. If resistance 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Red wire between speed control servo and brake switch.
12. Ensure ignition is off and speed control servo connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Using DVOM, measure resistance between terminal No. 3 (Yellow/Red wire) on brake switch connector and terminal No. 11 (Yellow/Red wire) on PCM connector C3. see scheme 6and see scheme 22. If resistance is less than 5 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance 5 ohms or more, repair open in Yellow/Red wire between brake switch and PCM.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. At this time, conditions required for DTC to be stored are not present. Ensure ignition is on with engine off. Using scan tool, go to FREEZE FRAME data and operate vehicle within FREEZE FRAME data parameters. If DTC SPECIFIC GOOD TRIP counter does not change to zero, test is complete. If DTC SPECIFIC GOOD TRIP counter changes to zero, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 3.
2. Turn ignition off. At this time, conditions required for DTC to be stored are not present. Inspect wiring and connectors between FPCM and ECM. FPCM located on top of fuel injection pump. (Scheme 30) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
3. Ensure ignition is off. Disconnect FPCM connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) Turn ignition on with engine off. Using DVOM, measure voltage at terminal No. 7 (Red/Light Green wire) on FPCM connector. see scheme 16 If voltage is 8 volts or more, go to next step. If voltage is less than 8 volts, perform «DTC P0215: FUEL INJECTION PUMP CONTROL CIRCUIT»(ref-97349-S42573244632001050200000) test.
4. Turn ignition off. Ensure FPCM connector is still disconnected. Disconnect ECM connector. Using 12-volt test light connected to battery voltage, check for voltage at terminal No. 6 (Black/Tan wire) on FPCM connector. see scheme 16 This is the ground circuit for FPCM. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open or high resistance on Black/Tan wire between FPCM and ground connection. Ground connection is located at ground connection for negative battery terminal.
5. Ensure ignition is off and FPCM connector and ECM connector are still disconnected. Using DVOM, measure resistance between terminal No. 2 (White wire) on FPCM connector and terminal No. 13 (White wire) on ECM connector. see scheme 12and see scheme 16. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in White wire between FPCM and ECM.
6. Ensure ignition is off and FPCM connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 2 (White wire) on FPCM connector. If resistance 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in White wire between FPCM and ECM.
7. Ensure ignition is off and FPCM connector and ECM connector are still disconnected. Using DVOM, measure resistance between terminal No. 1 (Black wire) on FPCM connector and terminal No. 23 (Black wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between FPCM and ECM.
8. Ensure ignition is off and FPCM connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Black wire) on FPCM connector. If resistance 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Black wire between FPCM and ECM.

1. Turn ignition on. Using scan tool, check for DTCs. If additional DTCs do not exist, go to next step. If any additional DTCs exist, repair set DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-97349-S11984774092001050200000).
2. Turn ignition on. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 5.
3. Turn ignition off. At this time, conditions required for DTC to be stored are not present. Inspect wiring and connectors between FPCM and ECM. FPCM located on top of fuel injection pump. (Scheme 30) ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
4. Check fuel injection pump timing. See CHECKING FUEL INJECTION PUMP TIMING under FUEL INJECTION PUMP TIMING in ON-VEHICLE ADJUSTMENTS - RAM PICKUP - DIESEL article. If fuel injection pump timing is okay, go to next step. If fuel injection pump timing requires adjustment, adjust fuel injection pump timing as necessary.
5. Ensure ignition is off. Disconnect FPCM connector. FPCM connector is located on end of fuel injection pump. (Scheme 30) Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using DVOM, measure resistance between terminal No. 8 (Dark Green wire) on FPCM connector and terminal No. 18 (Dark Green wire) on ECM connector. see scheme 12and see scheme 16. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green wire between FPCM and ECM.
6. Ensure ignition is off and FPCM connector and ECM connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 8 (Dark Green wire) on FPCM connector. If resistance 5 ohms or more, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is less than 5 ohms, repair short to ground in Dark Green wire between FPCM and ECM.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1691 does not exist, go to next step. If DTC P1691 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
2. Turn ignition on with engine off. Using scan tool, clear DTCs. Start engine and allow engine to idle for one minute. Using scan tool, check for DTCs. If DTC P1691 does not exist, test is complete. If DTC P1691 exists, replace fuel injection pump. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.

Using scan tool, clear DTCs from ECM. Using scan tool, check for stored DTCs in PCM. Perform appropriate test procedure for stored DTCs in PCM. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .

Turn ignition on with engine off. Using scan tool, clear DTCs from PCM. Using scan tool, check for stored DTCs in ECM. Perform appropriate test procedure for stored DTCs in ECM. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .

1. Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool displays BUS OPERATIONAL, go to next step. If scan tool does not display BUS OPERATIONAL, refer to symptoms displayed on scan tool to identify the bus failure and then diagnose and correct bus failure, see COMMUNICATIONS under SYSTEM TESTS in BODY CONTROL MODULES - RAM PICKUP article in ACCESSORIES & EQUIPMENT.
2. Ensure ignition is on with engine off. Using scan tool, clear DTCs from PCM. Turn ignition off and then back on again with engine off. Using scan tool, check for stored DTCs in PCM. If DTC P1694 exists, go to next step. If DTC P1694 does not exist, test is complete.
3. Turn ignition off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Connect jumper wire between ground and terminal No. 41 (Violet/Brown wire) on ECM connector. see scheme 12 Turn ignition on with engine off. Using scan tool, go to BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in Violet/Brown wire between ECM and Data Link Connector (DLC) terminal No. 7.
4. Turn ignition off. Ensure ECM connector is still disconnected. Connect jumper wire between ground and terminal No. 40 (White/Black wire) on ECM connector. Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in White/Black wire between ECM and Data Link Connector (DLC) terminal No. 11.
5. Turn ignition off. Ensure ECM connector is still disconnected. Using DVOM, measure resistance between ground and terminal No. 30 (Black/Tan wire) on ECM connector. If resistance is less than 10 ohms, replace ECM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 10 ohms or more, repair open in Black/Tan wire between ECM and ground connection. Ground connection is located at ground connection for negative battery terminal.

1. Turn ignition on with engine off. Using scan tool, perform SRI MEMORY TEST. If scan tool displays WRITE REFUSED, go to next step. If scan tool does not display WRITE REFUSED, test is complete.
2. Ensure ignition is on and engine is off. Using scan tool, perform SRI MEMORY TEST again. If scan tool does not display WRITE FAILURE, test is complete. If scan tool displays WRITE FAILURE, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. PCM is located at passenger's side rear corner of engine compartment. see scheme 3

1. Turn ignition on with engine off. Using scan tool, check for stored DTCs in PCM. If scan tool does not display NO RESPONSE to PCM, go to next step. If scan tool displays NO RESPONSE to PCM, go to «NO RESPONSE FROM PCM»(ref-97349-S11645977742001051600000) under SCAN TOOL COMMUNICATIONS.
2. Ensure ignition is on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool does not display BUS OPERATIONAL, go to next step. If scan tool displays BUS OPERATIONAL, test is complete.
3. Ensure ignition is on with engine off. Using scan tool, clear DTCs from Engine Control Module (ECM). Turn ignition off and then back on again with engine off. Using scan tool, check for stored DTCs in ECM. If DTC P1698 exists, go to next step. If DTC P1698 does not exist, test is complete.
4. Turn ignition off. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Connect jumper wire between ground and terminal No. 30 (Violet/Brown wire) on PCM connector C3. see scheme 22 Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in Violet/Brown wire between PCM and Data Link Connector (DLC) terminal No. 3.
5. Turn ignition off. Ensure PCM connectors are still disconnected. Connect jumper wire between ground and terminal No. 28 (White/Black wire) on PCM connector C3. Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the bus operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in White/Black wire between PCM and DLC terminal No. 11.
6. Turn ignition off. Ensure PCM connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 31 (Black/Tan wire) on PCM connector C1. If resistance is less than 10 ohms, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. If resistance is 10 ohms or more, repair open in Black/Tan wire between PCM and ground connection. Ground connection is located at ground connection for negative battery terminal.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is equal to zero, go to step 7.
2. Turn ignition off. At this time, conditions required for DTC to be stored are not present. Check and record FREEZE FRAME DATA. Try and recreate conditions that set DTC. Turn ignition on. Using scan tool, monitor P/N switch input state. Move gear shift lever through all gear selections. If scan tool does not display P/N and D/R, go to next step. If scan tool displays P/N and D/R, go to step 7.
3. Turn ignition off. Place gear shift lever in Park position. Record FREEZE FRAME DATA. Disconnect PCM connectors. PCM is located at passenger's side rear corner of engine compartment. see scheme 3 Check for faulty connections. Using DVOM, measure resistance between ground and terminal No. 6 (Black/White wire) on PCM connector C1. see scheme 22 While measuring resistance, move gear shift lever from Park to Reverse and back to Park position. If resistance does not change from less than 10 ohms to 10 ohms or more, go to next step. If resistance changes from less than 10 ohms to 10 ohms or more, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article.
4. If resistance is less than 10 ohms at all times, go to next step. If resistance is 10 ohms or more at all times, go to step 6.
5. Disconnect P/N switch connector. Using DVOM, measure resistance between ground and terminal No. 6 (Black/White wire) on PCM connector C1. If resistance is less than 5 ohms, repair short to ground in Black/White wire. If resistance is 5 ohms or more, replace P/N switch.
6. Disconnect P/N switch connector. Using DVOM, measure resistance of Black/White wire between terminal No. 6 on PCM connector C1 and terminal No. 2 of P/N switch connector. see scheme 21and see scheme 22. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace P/N switch.
7. Conditions required to set DTC are not present at this time. Check that displayed DTC matches the FREEZE FRAME DTC. Inspect wiring and connectors between P/N switch and PCM. P/N switch is located on side of transmission, below and to the rear of transmission shift lever. Repair wiring or connectors as necessary.

TEST VER-1A

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Supplemental Restraint System (SRS) module.

1. If ECM has been replaced, battery has been disconnected or APPS has been disconnected or replaced, go to next step. If ECM has not been replaced, battery has not been disconnected or APPS has not been disconnected or replaced, go to step 3 . NOTE: DO NOT attempt to adjust screws or disassemble APPS. Settings are preset at factory and should not be altered.
2. To program APPS, reassemble all components. Turn ignition on without starting engine. Slowly press accelerator pedal to floor once and slowly release. This procedure must only be done once to ensure APPS calibration has been programmed into the ECM.
3. If PCM has not been replaced, go to next step. If PCM has been replaced, connect scan tool to Data Link Connector (DLC). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB and SRS modules.
4. Inspect vehicle to ensure all components related to the repair are properly connected. Reassemble and reconnect components as necessary. Inspect engine oil for fuel contamination. Change engine oil and filter as necessary. Attempt to start engine.
5. If engine starts, test is complete. If engine does not start, check for related technical service bulletins (TSBs) and go to appropriate no-start diagnostic procedure in TROUBLE SHOOTING - NO CODES - RAM PICKUP - DIESEL article for additional testing.

TEST VER-2A

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Supplemental Restraint System (SRS) module.

1. If ECM has been replaced, battery has been disconnected or APPS has been disconnected or replaced, go to next step. If ECM has not been replaced, battery has not been disconnected or APPS has not been disconnected or replaced, go to step 3 . NOTE: DO NOT attempt to adjust screws or disassemble APPS. Settings are preset at factory and should not be altered.
2. To program APPS, reassemble all components. Turn ignition on without starting engine. Slowly press accelerator pedal to floor once and slowly release. This procedure must only be done once to ensure APPS calibration has been programmed into the ECM.
3. If PCM has not been replaced, go to next step. If PCM has been replaced, connect scan tool to Data Link Connector (DLC). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB and SRS modules.
4. If this test is being performed after a non code related test, check if initial symptom still exists. If initial symptom no longer exists, test is complete. If initial symptom or another symptom exists, repair is not complete. Check for technical service bulletins (TSBs) which apply to the symptom.
5. If this test is being performed after a DTC test, connect scan tool to Data Link Connector (DLC). Using scan tool, clear DTCs and reset all memory values.
6. If test is being performed after an A/C relay control circuit DTC test, ensure A/C is turned on during road test. Road test vehicle for at least 5 minutes with vehicle at a speed of at least 40 MPH. At some point during road test, stop vehicle and turn engine off for at least 10 seconds. Start engine and continue road test. Ensure transmission shifts through all gears. After road test, turn engine off and go to next step.
7. Using scan tool, check for DTCs. If no DTCs exist, repair is complete. If any DTCs exist, perform appropriate DTC test.

TEST VER-3A

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Supplemental Restraint System (SRS) module.

1. If ECM has been replaced, battery has been disconnected or APPS has been disconnected or replaced, go to next step. If ECM has not been replaced, battery has not been disconnected or APPS has not been disconnected or replaced, go to step 3 . NOTE: DO NOT attempt to adjust screws or disassemble APPS. Settings are preset at factory and should not be altered.
2. To program APPS, reassemble all components. Turn ignition on without starting engine. Slowly press accelerator pedal to floor once and slowly release. This procedure must only be done once to ensure APPS calibration has been programmed into the ECM.
3. If PCM has not been replaced, go to next step. If PCM has been replaced, connect scan tool to Data Link Connector (DLC). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB and SRS modules.
4. Inspect vehicle to ensure all components related to the repair are properly connected. Reassemble and reconnect components as necessary. Connect scan tool to Data Link Connector (DLC). Using scan tool, clear DTCs.
5. To ensure no charging system problems exist, start engine. Increase engine speed to 2000 RPM for at least 30 seconds. Allow engine to idle. Shut engine off.
6. Turn ignition on. Using scan tool, check for DTCs. If no DTCs exist, repair is complete. If repaired DTC has reset or another DTC has set, test is not complete. Checked for related technical service bulletins and perform appropriate DTC test.

TEST VER-4A

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Supplemental Restraint System (SRS) module.

1. If ECM has been replaced, battery has been disconnected or APPS has been disconnected or replaced, go to next step. If ECM has not been replaced, battery has not been disconnected or APPS has not been disconnected or replaced, go to step 3 . NOTE: DO NOT attempt to adjust screws or disassemble APPS. Settings are preset at factory and should not be altered.
2. To program APPS, reassemble all components. Turn ignition on without starting engine. Slowly press accelerator pedal to floor once and slowly release. This procedure must only be done once to ensure APPS calibration has been programmed into the ECM.
3. If PCM has not been replaced, go to next step. If PCM has been replaced, connect scan tool to Data Link Connector (DLC). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB and SRS modules.
4. Inspect vehicle to ensure all components related to the repair are properly connected. Reassemble and reconnect components as necessary. Connect scan tool to Data Link Connector (DLC). Using scan tool, clear DTCs.
5. To ensure no speed control system problem exists, road test vehicle at a speed of more than 30 MPH. Depress steering wheel speed control ON/OFF switch to ON position. Depress and release steering wheel speed control SET switch. Verify that speed control engages.
6. If speed control engages, go to next step. If speed control does not engage, test is not complete. Check for related Technical Service Bulletins (TSBs) and any speed control related DTCs. Perform appropriate DTC test if necessary.
7. With speed control engaged, quickly press and release steering wheel speed control RESUME/ACCEL switch. Verify that vehicle speed increases by 2 MPH. Release RESUME/ACCEL switch. If vehicle speed increases by 2 MPH, go to next step. If vehicle speed does not increase by 2 MPH, test is not complete. Check for related TSB and any speed control related DTCs.
8. Depress and hold steering wheel speed control COAST switch. Verify that vehicle speed decreases. If vehicle speed decreases, go to next step. If vehicle speed does not decrease, test is not complete. Check for related TSB and any speed control related DTCs. Release COAST switch.
9. Using caution, depress and release brake pedal. Verify that speed control disengages. If vehicle speed disengages, go to next step. If vehicle speed does not disengage, test is not complete. Check for related TSB and any speed control related DTCs.
10. Ensure vehicle speed is more than 25 MPH. Depress steering wheel speed control RESUME/ACCEL switch. Verify that previously set vehicle speed is obtained. If previously set vehicle speed is obtained, go to next step. If previously set vehicle speed is not obtained, test is not complete. Check for related TSB and any speed control related DTCs. Release steering wheel speed control RESUME/ACCEL switch.
11. Depress steering wheel speed control SET switch and ensure vehicle speed decreases. Increase vehicle speed to at least 30 MPH. Release steering wheel speed control SET switch. Verify that speed control engages and speed is maintained. If speed control engages and speed is maintained, go to next step. If speed control does not engage and speed is not maintained, test is not complete. Check for related TSB and any speed control related DTCs.
12. With speed control engaged, depress and release steering wheel speed control CANCEL switch. Verify that speed control disengages. If speed control disengages, go to next step. If speed control does not disengage, test is not complete. Check for related TSB and any speed control related DTCs.
13. Increase vehicle speed to at least 35 MPH and engage speed control. Depress and release steering wheel speed control ON/OFF switch to OFF position. Verify that speed control disengages. Go to next step. If speed control does not disengage, test is not complete. Check for related TSB and any speed control related DTCs.
14. If all of the functions listed in steps 5 - 13 operate properly, test is complete. If any or all of the functions listed in steps 5 - 13 do not operate properly, repair is not complete. Check for related TSB and any speed control related DTCs. Perform appropriate DTC test if necessary.

TEST VER-5A

Note. When battery is disconnected, Engine Control Module (ECM) is disconnected or replaced, or Accelerator Pedal Position Sensor (APPS) has been disconnected or replaced, ECM must be programmed to match the APPS. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Supplemental Restraint System (SRS) module.

1. If ECM has been replaced, battery has been disconnected or APPS has been disconnected or replaced, go to next step. If ECM has not been replaced, battery has not been disconnected or APPS has not been disconnected or replaced, go to step 3 . NOTE: DO NOT attempt to adjust screws or disassemble APPS. Settings are preset at factory and should not be altered.
2. To program APPS, reassemble all components. Turn ignition on without starting engine. Slowly press accelerator pedal to floor once and slowly release. This procedure must only be done once to ensure APPS calibration has been programmed into the ECM.
3. If PCM has not been replaced, go to next step. If PCM has been replaced, connect scan tool to Data Link Connector (DLC). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB and SRS modules.
4. Connect scan tool to Data Link Connector (DLC). Using scan tool, check for DTCs. If no DTCs exist, go to next step. If any DTCs exists, perform appropriate DTC test. NOTE: The best way to ensure OBD-II DTC repair is complete is to allow ECM to run appropriate TRIP to increment the GOOD TRIP counter which verifies that repair was successful. A component DTC will require 2 minutes of engine run time without any DTCs to increment the GOOD TRIP counter. A monitor DTC other than a misfire DTC will require using scan tool pre-test screens to allow technician to meet requirements that must be performed to run the monitor. A misfire DTC will require using SIMILAR CONDITIONS window on scan tool to attempt to duplicate operating conditions when DTC was set to verify repair is complete.
5. Connect scan tool to DLC. Ensure at 1/4 tank of fuel exists, all accessories are off. If this verification test is being performed after a component DTC repair, go to next step. If this verification test is being performed after a MONITOR DTC repair, go to step 7 . If this verification test is being performed after a MISFIRE DTC repair, go to step 8 .
6. Ensure ignition has been off for at least 10 seconds. Start engine and operate engine for 2 minutes. If the STARTS SINCE SET and GOOD TRIP counter displays change to one or more, repair is complete. Clear any DTCs and disconnect scan tool. If the STARTS SINCE SET and GOOD TRIP counter displays do not change to one or more, check for other DTCs that may have been set during the test. Perform appropriate DTC test.
7. Using scan tool, monitor pre-test enabling conditions until all conditions have been meet to run appropriate monitor. Run monitor for repaired DTC. If new DTC is set, perform appropriate DTC test. If repaired DTC is reset or monitor for repaired DTC fails to run, repair is not complete. Check for related TSB and perform appropriate DTC test. If monitor ran and GOOD TRIP counter changes to one or more, repair was successful. Disconnect scan tool.
8. Using scan tool, monitor SIMILAR CONDITIONS window on scan tool while attempting to duplicate operating conditions when DTC was set. If operating conditions can be duplicated, GOOD TRIP counter should change to one or more, repair was successful. If new DTC is set, perform appropriate DTC test. If repaired DTC is reset, repair is not complete. Check for related TSB and perform appropriate DTC test. If monitor ran and GOOD TRIP counter changes to one or more, repair was successful. Disconnect scan tool.