Possible Causes

• Network communication concern
• GWM
• PCM

Fig 1: Anti-Lock Brake System-A (ABS-A) Module Connector - C135A

Courtesy of FORD MOTOR CO.

Harness Side

Fig 2: Anti-Lock Brake System-B (ABS-B) Module Connector - C135B

Courtesy of FORD MOTOR CO.

Harness Side

Fig 3: Gateway Module A (GWM) Connector - C2431

Courtesy of FORD MOTOR CO.

Harness Side

1. AI1: CHECK THE PCM COMMUNICATION 
   • Ignition ON, engine OFF.
   • Press the Read Vehicle Information button to view the results of the modules communicating on the network.
   • Retrieve the continuous memory DTCs.
   • Does the PCM pass the Network Test? 

     Yes	No
     RETRIEVE and RECORD all PCM DTCs. REFER to the appropriate Electronic Engine Controls article or the Engine Controls article. If there are no DTCs in the PCM, Go to  AI3.	Go to  AI2.

2. AI2: CHECK THE GWM COMMUNICATION 
   • Review the results of the modules communicating on the network from the previous step.
   • Did the GWM pass the Network Test? 

     Yes	No
     DIAGNOSE the PCM does not communicate with the diagnostic scan tool. REFER to the Module Communications Network article.	DIAGNOSE the scan tool does not communicate with the GWM. REFER to the Module Communications Network article.

3. AI3: RECHECK THE ABS MODULE FOR THE LOST COMMUNCATION DTC 
   • Clear the ABS DTCs.
   • 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, engine OFF.

     Carry out the ABS self-test.

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

     Yes	No
     Go to  AI4.	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. AI4: REVIEW THE ABS 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	No
     For DTC U3003:16, GO to PINPOINT TEST A . For DTC U3003:17, GO to PINPOINT TEST F .	Go to  AI5.

5. AI5: CHECK FOR GWM DTCS 

   Carry out the GWM self-test.

   • Are any DTCs present? 

     Yes	No
     DIAGNOSE the GWM DTC. REFER to the Module Communications Network article.	Go to  AI6.

6. AI6: CHECK FOR PCM DTCS 

   Carry out the PCM KOEO self-test.

   • Are any DTCs present? 

     Yes	No
     DIAGNOSE the PCM DTC. REFER to the appropriate Electronic Engine Controls article.	Go to  AI7.

7. AI7: 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	No
     Go to  AI8.	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

8. AI8: CHECK FOR COMMUNICATION DTCS IN OTHER MODULES 
   • Ignition ON, engine OFF.
   • Retrieve the continuous memory DTCs.
   • Is any DTC from the Fault Trigger Conditions Table set in 1 or more modules in addition to the ABS module? 
9. AI9: VERIFY PCM OPERATION
   • Ignition OFF.
10. AI10: VERIFY ABS MODULE OPERATION 
    • Ignition OFF.
    • ABS Module connector disconnected.
    • GWM connector disconnected. (C2431)
11. AI11: VERIFY ABS OPERATION 
    • Ignition OFF.
    • ABS_A Module connector disconnected. (C135A)
    • ABS_B Module connector disconnected. (C135B)
    • GWM connector disconnected. (C2431)