LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2024 >> Mustang EcoBoost, 2D Convertible >> Repair and Diagnosis (Single Page) >> Brakes >> Anti-Lock Brakes >> Anti-Lock Brake System (Abs) And Stability Control >> Diagnosis And Testing >> Anti-Lock Brake System (ABS) and Stability Control >> Pinpoint Tests >> Pinpoint Test Ah: Abs Module Communication Concern With Pcm >> Pinpoint Test Ah: Abs Module Communication Concern With Pcm
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test Ah: Abs Module Communication Concern With Pcm

  1. Normal Operation and Fault Conditions 

    With the ignition ON, the PCM sends messages to the ABS module over the FD-CAN1. If the ABS module does not receive these messages within a certain time frame (usually less than 1 second), the ABS module sets a DTC. For information on the messages sent to the ABS module by the PCM, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

    The TCM is and internal component of the PCM.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    ABS C1137:64 Reverse gear switch: Signal Plausibility Failure This DTC sets if a failure is detected when the reverse gear switch is active during drive off, when the yaw rate signal and lateral acceleration signal are available and stationary forward curve driving is recognized. Or, if there is a toggling of the reverse gear switch during a not clutch pressed condition and vehicle speed is higher than 11 km/h (7 mph).
    ABS U0100:87 Lost Communication With ECM/PCM 'A': Missing Message This DTC sets when the ABS module does not receive any messages from the PCM within the allowed time.
    ABS U0101:87 Lost Communication with TCM: Missing Message This DTC sets when the ABS module does not receive any messages from the PCM within the allowed time.
    ABS U0401:00 Invalid Data Received from ECM/PCM A: No Sub Type Information This DTC sets when the ABS module receives invalid data in any of the following messages: accelerator pedal, brake pedal, driven wheel torque or neutral tow status.
    ABS U0401:64 Invalid Data Received from ECM/PCM A: Signal Plausibility Failure This DTC sets when the ABS module receives invalid data in the gear selector position or driven wheel torque messages.
    ABS U0401:82 Invalid Data Received from ECM/PCM A: Alive/Sequence Counter Incorrect/Not Updated This DTC sets when the ABS module receives invalid data in the transmission gear neutral status message.
    ABS U0401:83 Invalid Data Received from ECM/PCM A: Value Of Signal Protection Calculation Incorrect This DTC sets when the ABS module receives invalid data in the transmission gear neutral status message.
    ABS U0401:86 Invalid Data Received from ECM/PCM A: Signal Invalid This DTC sets when the ABS module receives invalid data in the accelerator pedal message.
    ABS U0402:82 Invalid Data Received from TCM: Alive/Sequence Counter Incorrect/Not Updated This DTC sets when the ABS module receives invalid data in the gear lever position message.
    ABS U0402:83 Invalid Data Received from TCM: Value Of Signal Protection Calculation Incorrect This DTC sets when the ABS module receives invalid data in the gear lever position message.
    ABS U0402:86 Invalid Data Received from TCM: Signal Invalid This DTC sets when the ABS module receives invalid data in the gear lever position message.

    Possible Causes 

    • Network communication concern
    • PCM
    • ABS module

    Visual Inspection and Pre-checks 

    • Make sure the vehicle battery state of charge is at least 80%
    • Make sure the vehicle battery voltage is at least 11 VDC

  2. AH1 CHECK THE PCM (POWERTRAIN CONTROL MODULE) COMMUNICATION

    • Ignition ON.

    • Using a diagnostic scan tool, carry out the PCMKOEO self-test. Only available in the service information

    Does the PCM communicate with the diagnostic scan tool and return DTCs ' 

    Yes  RETRIEVE and RECORD all PCMDTCs. REFER to: Electronic Engine Controls . REFER to: Electronic Engine Controls . . If there are no DTCs in the PCM, GO to  AH2.
    No  DIAGNOSE the scan tool does not communicate with the PCM. REFER to: Controller Area Network (CAN) Module Communications Network .

  3. AH2 RECHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE FOR THE LOST COMMUNICATION DTC (DIAGNOSTIC TROUBLE CODE)

    • Using a diagnostic scan tool, clear the ABS module Diagnostic Trouble Codes (DTCs). Only available in the service information

    • Ignition OFF.

    • Ignition ON.

    • NOTE: When retrieving DTCs, ignore all historical or continuous memory DTCs.

      Using a diagnostic scan tool, carry out the ABS module self-test. Only available in the service information

    Are any of the DTCs listed in the DTC Fault Trigger Conditions table present and active in the ABS module? 

    Yes  GO to  AH3.
    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. AH3 REVIEW THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE SELF-TEST FOR VOLTAGE-REALTED DTCS

    • Review the results from the ABS module self-test.

    Is DTC U3003:16 or U3003:17 present? 

    Yes  For DTC U3003:16, GO to Pinpoint Test A  For DTC U3003:17, GO to Pinpoint Test F 
    No  GO to  AH4

  5. AH4 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) DTCS

    • Using a diagnostic scan tool, carry out the PCMKOEO self-test. Only available in the service information

    Are any DTCs present and active in the PCM ' 

    Yes  RETRIEVE and RECORD all PCMDTCs. REFER to: Electronic Engine Controls . REFER to: Electronic Engine Controls .
     
    No  GO to  AH5.

  6. AH5 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

    • NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.

      Check the vehicle service history for recent service actions related to the PCM or the ABS module. If recent service history is found:

      • Verify the correct replacement module was installed. HVBOM may be used to verify correct part fitment.
      • Verify the configuration of replacement module was correct. Re-configure the module using as-built data if prior configuration is suspect.
      • Verify the module was not obtained from a like vehicle and installed into customer vehicle. Return the swapped module to source vehicle and obtain new replacement module.

    • Operate the system and determine if the observable symptom is still present.

    Is the observable symptom still present? 

    Yes  GO to  AH6.
    No  The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

  7. AH6 CHECK FOR COMMUNICATION DTCS IN OTHER MODULES

    • Ignition ON.

    • NOTE: When retrieving DTCs, ignore all historical or continuous memory DTCs.

      Using a diagnostic scan tool, carry out a Network Test.

    Is any DTC from the Fault Trigger Conditions Table set in 1 or more modules in addition to the ABS module? 

    Yes  GO to  AH7.
    No  GO to  AH8

  8. AH7 VERIFY PCM (POWERTRAIN CONTROL MODULE) OPERATION

    • Ignition OFF.

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    2.3L EcoBoost (201kW/273PS): 

    2.3L EcoBoost (201kW/273PS): 

    • Disconnect ABS Module C135.

    • Using a good light source, inspect all disconnected electrical connectors for the following:

      • corrosion - install new connector or terminal and clean the module pins
      • damaged or bent pins - install new terminals or pins
      • pushed-out pins - install new pins as necessary
      • spread terminals - install new terminals as necessary

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    • Connect PCM C175B Make sure the connector seats and latches correctly.

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    • Connect PCM C175E Make sure the connector seats and latches correctly.

    2.3L EcoBoost (201kW/273PS): 

    • Connect PCM C1551B Make sure the connector seats and latches correctly.

    2.3L EcoBoost (201kW/273PS): 

    • Connect PCM C1551E Make sure the connector seats and latches correctly.

    • Connect ABS Module C135 Make sure the connector seats and latches correctly.

    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any 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 Powertrain Control Module (PCM). Only available in the service information RVC: 
    Generate RVC only works in single-step view Generate RVC requires VIN entry  . REFER to: Powertrain Control Module (PCM) . REFER to: Powertrain Control Module (PCM) .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.

  9. AH8 VERIFY ABS (ANTI-LOCK BRAKE SYSTEM) OPERATION

    • Ignition OFF.

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    2.3L EcoBoost (201kW/273PS): 

    2.3L EcoBoost (201kW/273PS): 

    • Disconnect ABS Module C135.

    • Using a good light source, inspect all disconnected electrical connectors for the following:

      • corrosion - install new connector or terminal and clean the module pins
      • damaged or bent pins - install new terminals or pins
      • pushed-out pins - install new pins as necessary
      • spread terminals - install new terminals as necessary

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    • Connect PCM C175B Make sure the connector seats and latches correctly.

    5.0L 32V Ti-VCT, 5.0L Ti-VCT V8 (331kW/450PS) (MF), 5.0L 32V Ti-VCT (359kW/486PS) (WU): 

    • Connect PCM C175E Make sure the connector seats and latches correctly.

    2.3L EcoBoost (201kW/273PS): 

    • Connect PCM C1551B Make sure the connector seats and latches correctly.

    2.3L EcoBoost (201kW/273PS): 

    • Connect PCM C1551E Make sure the connector seats and latches correctly.

    • Connect ABS Module C135 Make sure the connector seats and latches correctly.

    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any 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 EBB unit. REFER to: Electric Brake Booster (EBB) .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
scientia non olet · About LEMON Manuals