Pinpoint Test G: U0100
- Refer to TRAILER/CAMPER ADAPTER
for schematic and connector information.
Normal Operation and Fault Conditions
With the ignition ON, the PCM sends messages to the TBM over the HS-CAN. If the TBM does not receive these messages within the specified time frame, the TBM sets a DTC. This can be due to a PCM failure, a circuit failure on the HS-CAN or an excessive load on the network. For information on the messages sent to the TBM by the PCM, REFER to: Auxiliary Brake System - Vehicles With: Trailer Brake Control - System Operation and Component Description .
DTC Fault Trigger Conditions
- DTC Fault Trigger Conditions
- TBM U0100 -- Lost Communication with the ECM / PCM
- This DTC sets in continuous memory and on-demand if the TBM does not receive any network messages from the PCM.
Possible Sources
- Network communication concern
- PCM
- TBM
- G1 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Using a diagnostic scan tool, carry out the Network Test.
Does the PCM pass the Network Test?
Yes GO to G2 No DIAGNOSE the PCM does not communicate with the diagnostic scan tool, REFER to: COMMUNICATIONS NETWORK . - G2 CHECK THE TBM (TRAILER BRAKE CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)
- Using a diagnostic scan tool, carry out the TBM self-test.
- Clear the TBM Diagnostic Trouble Codes (DTCs).
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds for all modules to wake up and prove out.
- Using a diagnostic scan tool, carry out the TBM self-test.
- Record the TBM Diagnostic Trouble Codes (DTCs).
Is DTC U0100 retrieved again?
Yes GO to G3 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - G3 REVIEW THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE TBM (TRAILER BRAKE CONTROL MODULE) SELF-TEST
- Review the recorded Diagnostic Trouble Codes (DTCs) from the TBM self-test.
Is DTC B1317 or B1318 present?
Yes For DTC B1317, GO to Pinpoint Test D For DTC B1318, GO to Pinpoint Test E No GO to G4 - G4 RETRIEVE THE DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE PCM (POWERTRAIN CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, carry out the PCM KOEO self-test.
Is DTC P0562 or P0563 present?
Yes DIAGNOSE the PCM Diagnostic Trouble Codes (DTCs). REFER to: appropriate Electronic Engine Controls article . No GO to G5 - G5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0100:XX SET IN OTHER MODULES
- Using a diagnostic scan tool, carry out the self-test for all modules.
- Retrieve the Continuous Memory Diagnostic Trouble Codes (CMDTCs) from all modules.
Is DTC U0100:xx set in 1 or more modules in addition to the ABS module?
Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new PCM. Refer to PCM GUIDED ROUTINE TESTING . No CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new TBM. REFER to: Trailer Brake Control Module (TBM) .