Possible Causes

• Wiring, terminals or connectors
• Network communication concern
• GWM
• IPC
• ABS module

Fig 1: Gateway Module A (GWM) Connector - C2431

Courtesy of FORD MOTOR CO.

Harness Side

1. BJ1: CHECK THE COMMUNICATION NETWORK 
   • Ignition ON, engine OFF.
   • Using a diagnostic scan tool, carry out the Network Test.
   • Do the GWM and IPC pass the Network Test? 

     Yes	No
     Go to  BJ2.	DIAGNOSE the no communication with the GWM or IPC. REFER to the Module Communications Network article.

2. BJ2: CHECK THE ABS CMDTCS 
   • Clear the ABS DTCs.
   • Ignition OFF.
   • Ignition ON, engine OFF.

     Carry out the ABS self-test.

   • Retrieve and record the ABS module DTCs.
   • Is DTC U0155:00 retrieved again? 

     Yes	No
     Go to  BJ3.	If no DTCs are present, the system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. For all others, GO to the DTC Chart: ABS Module.

3. BJ3: REVIEW THE RECORDED DTCS FROM THE ABS MODULE SELF-TEST 
   • Review the recorded DTCs from the ABS module self-test.
   • Is DTC U3003:16 or U3003:17 recorded? 

     Yes	No
     For DTC U3003:17, GO to PINPOINT TEST F . For DTC U3003:16, GO to PINPOINT TEST A .	Go to  BJ4.

4. BJ4: CHECK FOR DTCS IN THE GWM 

   Carry out the GWM self-test.

   • Are any DTCs present in the GWM? 

     Yes	No
     DIAGNOSE the GWM DTCs. REFER to the Module Communications Network article.	Go to  BJ5.

5. BJ5: CHECK FOR DTCS IN THE IPC 

   Carry out the IPC self-test.

   • Are any DTCs present in the IPC? 

     Yes	No
     DIAGNOSE the IPC DTCs. REFER to the Instrumentation, Message Center and Warning Chimes article.	Go to  BJ6.

6. BJ6: 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 IPC 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  BJ7.	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

7. BJ7: CHECK FOR DTC U0155:XX SET IN OTHER MODULES 
   • Retrieve the continuous memory DTCs.
   • Is DTC U0155:xx set in 1 or more modules in addition to the ABS module? 

     Yes	No
     Go to  BJ8.	Go to  BJ9.

8. BJ8: CHECK FOR CORRECT IPC OPERATION 
   • Ignition OFF.
9. BJ9: CHECK FOR CORRECT ABS MODULE OPERATION 
   • Ignition OFF.
   • ABS Module connector disconnected.
   • GWM connector disconnected. (C2431)