Final Drive Control Module (Fdcm) - Electrical Diagnostics: Diagnosis RAM Pickup 3500

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Scheme 621

For a complete wiring diagram refer to appropriate SYSTEM WIRING DIAGRAMS article .

Diagnostic Test

1. FINAL DRIVE CONTROL MODULE The Final Drive Control Module has detected an internal failure. View repair Repair Replace the Final Drive Control Module (FDCM) in accordance with the Service Information. Perform the FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) .

Scheme 622

For a complete wiring diagram refer to appropriate SYSTEM WIRING DIAGRAMS article .

1. VERIFY DTC IS ACTIVE NOTE: Make sure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding. Ignition on, engine not running. With the scan tool, read DTCs. Is this DTC active? Yes Go To 2 . No Go To 5 .
2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS With the scan tool, read all active DTCs from all modules. Check for: TIPM configuration. CAN B or C hardware electrical. VIN Missing/Mismatch. Battery or ignition related DTCs. Does the scan tool display any active DTCs to the conditions listed above? Yes Perform the appropriate diagnostic procedures, or. Refer to appropriate Electrical Diagnostic Information . Refer to appropriate Electrical Diagnostic Information . No Go To 3 .
3. VERIFY THAT THE ECM/PCM IS ACTIVE ON THE BUS Ignition on, engine not running. With the scan tool, select Network Diagnostics. Verify that the PCM is active on the bus. Is the PCM active on the bus? Yes Go To 4 . No Perform the appropriate diagnostic procedure. Refer to appropriate Electrical Diagnostic Information .
4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS With the scan tool, select Network Diagnostics. Is there more than one module with active DTC "Logged Against" the PCM? Yes Replace the Powertrain Control Module (PCM) in accordance with the service information. Perform the POWERTRAIN VERIFICATION TEST. Refer to «BODY VERIFICATION TEST»(ref-457926-S40044966262012030200000) for 1500, 2500 & 3500, or «BODY VERIFICATION TEST»(ref-457927-S20352278932012030200000) for 3500 CAB & CHASSIS, 4500 & 5500 . No Replace the module that set this DTC in accordance with the service information. Perform the FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) .
5. INTERMITTENT WIRING AND CONNECTORS The conditions necessary to set this DTC are not present at this time. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle test the wiring harness and connectors while checking for shorted and open circuits. Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset. Were there any problems found? Yes Repair as necessary. Perform the FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) . No Test complete.

1. ACTIVE DTC Ignition on, engine not running. With the scan tool, erase DTCs. Cycle the ignition key on and off several times. With the scan tool, read DTCs. Does the DTC reset? Yes Go To 2 . No Go To 4 .
2. COMMUNICATE WITH CLUSTER With the scan tool, attempt to communicate with the Instrument Cluster. Can communication be established with the Instrument Cluster? Yes Go To 3 . No Refer to «U0155-LOST COMMUNICATION WITH CLUSTER/CCN»(ref-457926-S20590538232012030200000) for 1500, 2500 & 3500 or «U0155-LOST COMMUNICATION WITH CLUSTER/CCN»(ref-457927-S23699983282012030200000) for 3500 CAB & CHASSIS, 4500 & 5500 and perform the U0155-Lost Communication with Cluster/CCN diagnostic procedure .
3. INSTRUMENT CLUSTER OPERATION Start the engine Allow the engine to idle. Is the correct engine speed display in the instrument cluster (Tach)? Yes Replace and program the Powertrain Control Module in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST. Refer to appropriate Electrical Diagnostic Information . No Refer to «Diagnosis and Testing»(ref-457880-S08881951252012030200000) and perform the appropriate diagnostic procedure.
4. INTERMITTENT WIRING AND CONNECTORS The conditions necessary to set this DTC are not present at this time. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle test the wiring harness and connectors while checking for shorted and open circuits. Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset. Were there any problems found? Yes Repair as necessary. Perform FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) . No Test complete.

1. CHECK FOR DTC U0401-IMPLAUSIBLE DATA RECEIVED FROM PCM NOTE: This DTC must be active for the results of this test to be valid. Turn the ignition on. With the scan tool, record and erase DTCs. Cycle the ignition switch from off to on. With the scan tool, read DTCs. Does the scan tool display: U0401-IMPLAUSIBLE DATA RECEIVED FROM PCM? Yes Go To 2 . No Go To 4 .
2. CHECK IF TIPM CAN BUS DTCS ARE PRESENT With the scan tool, read TIPM DTCs. Are there any TIPM CAN BUS DTCs present? Yes Refer to appropriate Electrical Diagnostic Information and perform the appropriate CAN Bus diagnostic procedure. . No Go To 3 .
3. PCM DTCS ARE PRESENT With the scan tool, read Powertrain Control Module DTCs. Are there any PCM DTCs present? Yes Refer to appropriate Electrical Diagnostic Information and perform the appropriate diagnostic procedure. . No Replace the Final Drive Control Module (FDCM) in accordance with the Service Information. Perform FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) .
4. INTERMITTENT WIRING AND CONNECTORS The conditions necessary to set this DTC are not present at this time. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle test the wiring harness and connectors while checking for shorted and open circuits. Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset. Were there any problems found? Yes Repair as necessary. Perform the FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) . No Test complete.

1. TOTALLY INTEGRATED POWER MODULE (TIPM) DTCS PRESENT Ignition on, engine not running. With the scan tool, read DTCs. Are there any DTCs present? Yes Perform the appropriate diagnostic procedure. Refer to appropriate Electrical Diagnostic Information . No Replace the Final Drive Control Module (FDCM) in accordance with the Service Information. Perform FDCM VERIFICATION TEST. Refer to «Standard Procedure»(ref-457882-S11221221782012030200000) .

1. Disconnect all jumper wires and reconnect all previously disconnected components and connectors. With the scan tool, select clear Stored DTCs. Make sure that all accessories are turned off and that the battery is fully charged. Test drive the vehicle in each Transfer Case range and verify proper operation in each range. To select or deselect 2WD, AWD or 4HI mode (if equipped), vehicle speed must be below 88 Kmh (55 mph) with all wheels at vehicle speed. Shifts will not take place with a wheel speed difference of greater than 21 Kmh (13 mph) between the front and rear wheels. To select or deselect 4LO (if equipped), vehicle speed must be below 5 Kmh (3 mph) with the ignition on, engine not running and the transmission in neutral (automatic transmission) or the clutch pedal pressed (manual transmission). To select or deselect Transfer Case Neutral (if equipped), vehicle speed must be 0 Kmh (0 mph) with the ignition on, engine not running, the brake pedal applied, and the transmission in neutral (automatic transmission) or the clutch pedal pressed (manual transmission). Press the Neutral button (if equipped) on the Transfer Case Selector Switch until the Neutral Indicator is illuminated. WARNING: Apply the parking brake. The vehicle may roll with the Transfer Case in neutral. To verify that the Transfer Case is in Neutral, shift the automatic transmission into reverse and release the brake pedal for three seconds or shift the manual transmission into gear and slowly release the clutch pedal. There should be no vehicle movement if the Transfer Case is in Neutral. With the scan tool, read DTCs in the Totally Integrated Power Module (TIPM) and in the Instrument Cluster (CCN). Are there any DTCs present in the TIPM or in the CCN? Yes Perform the appropriate diagnostic procedure or. Refer to «Diagnosis and Testing»(ref-457880-S08881951252012030200000) . Refer to «Diagnosis and Testing»(ref-457880-S08881951252012030200000) . No Test complete.

1. PERFORM FDCM VERIFICATION TEST CAUTION: Before removing the FDCM harness connector, clean the connector and locking cam area of dirt and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on the harness connector or module. Do not force the assist arm when releasing or installing the harness connector. NOTE: If the SKIM, PCM or FCM was replaced, refer to the service information for proper programming procedures. Disconnect all jumper wires and reconnect all previously disconnected components and connectors. Ensure that all accessories are turned off. Ensure that the battery is fully charged. With the scan tool, record and erase all DTC(s) from the FDCM Start and run the engine for 2 minutes while operating all functions of the system that caused the original concern. NOTE: When a Stabilizer System DTC diagnostic is complete and all repairs have been made, running the Stabilizer Motor System Test and/or LED System Test can also provide verification that the DTC has been repaired and the system is operating normally. Turn the ignition off, wait 5 seconds, then turn the ignition on. Using the scan tool, read DTC(s) from the FDCM. Are any FDCM DTC(s) present or is the original condition still present? Yes The repair is not complete. Refer to the related category for the DTC or symptom that is still present. No The repair is complete.