LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2024 >> Expedition Platinum, 4WD >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Anti-Lock Brake System (Abs) And Stability Control >> Diagnosis And Testing >> Anti-Lock Brake System (ABS) and Stability Control >> Pinpoint Tests >> Pinpoint Test Cl: Abs Module Communication Concern With APIM Or The Auto Hold Feature Is Inoperative, Disabled Or Cannot Be Enabled >> Pinpoint Test Cl: Abs Module Communication Concern With APIM Or The Auto Hold Feature Is Inoperative, Disabled Or Cannot Be Enabled
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test Cl: Abs Module Communication Concern With APIM Or The Auto Hold Feature Is Inoperative, Disabled Or Cannot Be Enabled

  1. Normal Operation and Fault Conditions 

    With the ignition ON, the APIM sends messages to the GWM over the HS-CAN3. The GWM relays these messages to the ABS module over the FD-CAN. If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC. This can be due to a APIM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the APIM, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

    Vehicles equipped with EPB are also equipped with an auto hold feature. This feature must be enabled by the driver by pressing the auto hold switch once the driver seatbelt is buckled and the driver door is closed. Pressing the auto hold switch enables the auto hold feature, but does not activate auto hold. When the switch is pressed, the APIM module sends a message to the ABS module indicating the system has been enabled. The ABS module then waits for messages from the RCM and BCM as well as ABS sensor information to indicate the auto hold feature can be activated. Once all criteria has been met, the ABS module activates the auto hold feature.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    ABS U0253:00 Lost Communication With Accessory Protocol Interface Module: No Sub Type Information This DTC sets when the ABS module does not receive any messages from the APIM within the allowed time.
    ABS U0554:86 Invalid Data Received From Accessory Protocol Interface Module: Signal Invalid This DTC sets when the ABS module receives messages from the APIM, but the messages contain invalid data.

    Possible Causes 

    • Network communication concern
    • GWM
    • APIM

  2. CL1 CHECK THE COMMUNICATION TO THE APIM (ACCESSORY PROTOCOL INTERFACE MODULE)

    • Ignition ON.

    • Using a diagnostic scan tool, retrieve the DTC s from the vehicle.
      NOTE: DTC s may be displayed from previous diagnostic actions.

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

    Does the APIM pass the network test? 

    Yes  Diagnose the APIMDTCs. REFER to: Information and Entertainment System . If there are no APIMDTCs, GO to  CL2
    No  GO to  CL2

  3. CL2 RECHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DTC (DIAGNOSTIC TROUBLE CODE) S

    • Put the ABS module in sleep mode by performing the following steps:

      • With ALL doors closed, set the ignition from ON to OFF.
      • Disconnect the diagnostic scan tool.
      • Open the door, exit the vehicle and close the door.
      • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.

    • Ignition ON.

    • Carry out the ABS self-test.

    Are any of the DTC s listed in the Fault Trigger Conditions Table retrieved again? 

    Yes  GO to  CL3
    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. CL3 CHECK FOR VOLTAGE DTC (DIAGNOSTIC TROUBLE CODE) S IN THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Review the recorded DTC s 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  CL4

  5. CL4 CHECK FOR APIM (ACCESSORY PROTOCOL INTERFACE MODULE) DTC (DIAGNOSTIC TROUBLE CODE) S

    • Using a diagnostic scan tool, carry out the APIM self-test.

    Is DTC U0253:xx or U0554:xx set in 1 or more modules in addition to the ABS module? 

    Yes  Diagnose the APIMDTCs. REFER to: Information and Entertainment System .
    No  GO to  CL5

  6. CL5 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 APIM or ABS. 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  CL6
    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. CL6 CHECK FOR COMMUNICATION DIAGNOSTIC TROUBLE CODES (DTCS) IN OTHER MODULES

    • Ignition ON.

    • Using a diagnostic scan tool retrieve all Diagnostic Trouble Codes (DTCs).

    Is any DTC from the Fault Trigger Conditions Table present in one or more modules in addition to the ABS ' 

    Yes  GO to  CL7
    No  GO to  CL8

  8. CL7 CHECK FOR CORRECT APIM (ACCESSORY PROTOCOL INTERFACE MODULE) MODULE OPERATION

    • Ignition OFF.

    • Disconnect APIM C240A .

    • Disconnect APIM C240B .

    • Disconnect APIM C240F .

    • Disconnect GWM C2341A

    • Disconnect GWM C2341C

    • Disconnect SASM C2414A

    • 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

    • Connect APIM C240A . Make sure it seats and latches correctly.

    • Connect APIM C240B . Make sure it seats and latches correctly.

    • Connect APIM C240F . Make sure it seats and latches correctly.

    • Connect SASM C2414A Make sure it seats and latches correctly.

    • Connect GWM C2341A Make sure it seats and latches correctly.

    • Connect GWM C2341C 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 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 exist,
    INSTALL a new Accessory Protocol Interface Module (APIM). Only available in the on-line service information RVC: 
    Generate RVC only works in single-step view Generate RVC requires VIN entry  REFER to: Accessory Protocol Interface Module (APIM) - Vehicles With: 12 Inch Screen . REFER to: Accessory Protocol Interface Module (APIM) - Vehicles With: 15 Inch Screen .
    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. CL8 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION

    • Put the ABS module in sleep mode by performing the following steps:

      • With ALL doors closed, set the ignition from ON to OFF.
      • Disconnect the diagnostic scan tool.
      • Open the door, exit the vehicle and close the door.
      • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.

    • Disconnect GWM C2341A

    • Disconnect GWM C2341C

    • Disconnect ABS Module connector C135.

    • Using a good light source, INSPECT the electrical connector 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

    • Connect APIM C240A. Make sure it seats and latches correctly.

    • Connect APIM C240B. Make sure it seats and latches correctly.

    • Connect APIM C240F. Make sure it seats and latches correctly.

    • Connect GWM C2341A Make sure it seats and latches correctly.

    • Connect GWM C2341C Make sure it seats and latches correctly.

    • Connect ABS module connector, C135. Make sure the connector 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 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 module. 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