Pinpoint Test H: U0121, U0415
- Refer to TRAILER/CAMPER ADAPTER
for schematic and connector information.
Normal Operation and Fault Conditions
With the ignition ON, the ABS module 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 ABS module 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 ABS module, REFER to: Auxiliary Brake System - Vehicles With: Trailer Brake Control - System Operation and Component Description .
DTC Fault Trigger Conditions
- DTC Fault Trigger Conditions
- TBM U0121 -- Lost Communication With Anti-Lock Brake System (ABS) Control Module
- This DTC sets in continuous memory and on-demand if the TBM does not receive any network messages from the ABS module.
- TBM U0415 -- Invalid Data Received from Anti-Lock Brake System (ABS) Control Module
- This DTC sets in continuous memory and on-demand if network message data the TBM receives from the ABS module is invalid instead of the actual message data.
Possible Sources
- Wiring, terminals or connectors
- ABS module
- TBM
- H1 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Using a diagnostic scan tool, carry out the Network Test.
Does the ABS module pass the Network Test?
Yes GO to H2 No DIAGNOSE the ABS module does not communicate with the diagnostic scan tool, REFER to: COMMUNICATIONS NETWORK . - H2 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 U0121 or U0415 retrieved again?
Yes GO to H3 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. - H3 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 in the TBM?
Yes For DTC B1317, GO to Pinpoint Test D For DTC B1318, GO to Pinpoint Test E No GO to H4 - H4 RETRIEVE THE DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE SELF-TEST
- Using a diagnostic scan tool, carry out the ABS module self-test.
Is DTC U3003:16 or U3003:17 present in the ABS module?
Yes DIAGNOSE the ABS module Diagnostic Trouble Codes (DTCs). REFER to: ANTI-LOCK BRAKE SYSTEM (ABS) AND STABILITY CONTROL . No GO to H5 - H5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0121:XX OR U0415: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 U0121:XX or U0415:XX set in 1 or more modules in addition to the TBM?
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 ABS. Refer to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . 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) .