LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2024 >> Bronco Big Bend, 2D Utility, Part Time T/Case Control, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 179 (MULTIFUNCTION Electronic Modules) >> Diagnosis And Testing >> Body Control Module C (BCMC) >> Pinpoint Tests >> Pinpoint Test A: U0100:87
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test A: U0100:87

WARNING: This page is about a different car, the 2023 Ford Bronco. However, it is still accessible from the selected car via links, so may be relevant.
  1. Refer to MODULE COMMUNICATION NETWORK for schematic and connector information.

    Normal Operation and Fault Conditions 

    REFER to: Controller Area Network (CAN) Module Communications Network - System Operation and Component Description .

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    BCMC U0100:87 Lost Communication With ECM/PCM 'A': Missing Message A continuous memory DTC that sets in the BCMC if powertrain data messages received from the PCM are missing.

    Possible Sources 

    • Communication network concern
    • Charging system concern
    • PCM
    • BCMC

    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 carried out.

  2. A1 VERIFY THE DIAGNOSTIC SCAN TOOL COMMUNICATES WITH THE PCM (POWERTRAIN CONTROL MODULE)

    • Connect the diagnostic tool.

    • Ignition ON.

    • Check that a vehicle session can be established using the diagnostic scan tool.

    Can a vehicle session be established? 

    Yes  GO to A2 
    No  REFER to: Controller Area Network (CAN) Module Communications Network .

  3. A2 RECHECK THE BCMC (BODY CONTROL MODULE C) 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 BCMC Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U0100:87 retrieved again? 

    Yes  GO to A3 
    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.

  4. A3 RETRIEVE THE PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

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

    Are any voltage system related DTCs present? 

    Yes  DIAGNOSE and REPAIR these DTCs first. REFER to the appropriate DTC Chart.
    No  GO to A4 

  5. A4 RETRIEVE THE BCMC (BODY CONTROL MODULE C) DIAGNOSTIC TROUBLE CODES (DTCS)

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

    Are any DTCs recorded? 

    Yes  DIAGNOSE and REPAIR these DTCs first. REFER to Diagnostic Trouble Code (DTC) Chart 
    No  GO to A5 

  6. A5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0100:87 SET IN OTHER MODULES

    • Using a diagnostic scan tool, clear the DTCs.

    • Ignition OFF.

    • Ignition ON.

    • Wait 10 seconds.

    • Using a diagnostic scan tool, retrieve all 

      Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U0100:87 set in other modules? 

    Yes  GO to A6 
    No  GO to A7 

  7. A6 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

    • Disconnect and inspect all PCM 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 all PCM 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 service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new PCM. Refer to PCM Guided Routine Testing
    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.

  8. A7 CHECK FOR CORRECT BCMC (BODY CONTROL MODULE C) OPERATION

    • Disconnect and inspect all BCMC 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 all BCMC 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 service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new BCMC. REFER to: Body Control Module C (BCMC) .
    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.
scientia non olet · About LEMON Manuals