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Pinpoint Test C : U0121:87

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during the PMI or the PMI may not have been performed.

  1. C1 CHECK THE COMMUNICATION NETWORK

    • Ignition ON.

    • Using a diagnostic scan tool, perform a network test.

    Does the ABS module pass the network test? 

    Yes  GO to  C2
    No  DIAGNOSE no communication with the ABS module. REFER to: Communications Network .

  2. C2 CHECK THE BCM (BODY CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)

    • Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs).

    • Wait 10 seconds.

    • Using a diagnostic scan tool, check the BCM Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U3006:16, U3006:17, U3007:16, U3007:17, U3013:16, U3013:17, U3014:16 or U3014:17 recorded? 

    Yes  For DTC U3006:16, U3007:16, U3013:16 or U3014:16, GO to Pinpoint Test J  For DTC U3006:17, U3007:17, U3013:17 or U3014:17, GO to Pinpoint Test K 
    No  GO to  C3

  3. C3 RETRIEVE THE DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Using a diagnostic scan tool, perform the ABS module self-test.

    Are any voltage system related Diagnostic Trouble Codes (DTCs) present? 

    Yes  REFER to: Anti-Lock Brake System (ABS) and Stability Control .
    No  GO to  C4

  4. C4 RECHECK THE BCM (BODY CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)

    • Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs).

    • Wait 10 seconds.

    • Using a diagnostic scan tool, check the BCM Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U0121:87 still present? 

    Yes  GO to  C5
    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.

  5. C5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0121:87 SET IN OTHER MODULES

    • Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs).

    • Ignition OFF.

    • Ignition ON.

    • Wait 10 seconds.

    • Using a diagnostic scan tool, retrieve all  Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U0121:87 set in other modules? 

    Yes  GO to  C6
    No  GO to  C7

  6. C6 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION

    • Ignition OFF.

    • Disconnect and inspect the ABS module and all related in-line connectors.

    • Repair:

      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary

    • Reconnect the ABS module and all related in-line connectors. Make sure it seats and latches correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, follow TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new ABS module. REFER to: Anti-Lock Brake System (ABS) Module .
    No  The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.

  7. C7 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

    • Ignition OFF.

    • Disconnect and inspect the BCM and all related in-line connectors.

    • Repair:

      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary

    • Reconnect the BCM and all related in-line connectors. Make sure they seat and latch correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, follow TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, Refer to BCM GUIDED ROUTINE .
    No  The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
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