Possible Causes

• Wiring, terminals or connectors
• Network communication concern
• ATCM

Fig 1: Antilock Braking System (ABS) Module Connector - C135

Courtesy of FORD MOTOR COMPANY

Harness Side

1. BM1: CHECK THE COMMUNICATION NETWORK 
   • 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 ATCM pass the network test? 

   Yes	No
   Go to  BM2.	REFER to the Module Communications Network article to diagnose the module not responding to the scan tool.

2. BM2: RECHECK FOR THE ABS MODULE DTCS 

   Carry out the ABS self-test.

   • Ignition OFF.
   • Ignition ON, engine OFF.

     Carry out the ABS self-test.

   • Record all ABS module DTCs.
   • Is DTC U0138:xx retrieved again? 

   Yes	No
   Go to  BM3.	The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

3. BM3: CHECK FOR VOLTAGE DTCS IN THE ABS MODULE 
   • Review the recorded DTCs from the ABS module self-test.
   • Is DTC U3003:16 or U3003:17 present? 

   Yes	No
   For DTC U3003:17, Go to PINPOINT TEST F . For DTC U3003:16, Go to PINPOINT TEST A .	Go to  BM4.

4. BM4: CHECK FOR DTCS IN THE ATCM 

   Carry out the ATCM self-test.

   • Record all DTCs from the ATCM self-test.
   • Are any DTCs present? 

   Yes	No
   DIAGNOSE the ATCM DTCs. REFER to the appropriate Diagnosis and Testing in the Four-Wheel Drive System article.	Go to  BM5.

5. BM5: 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 ATCM 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  BM6.	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

6. BM6: CHECK FOR COMMUNICATION DTCS SET IN OTHER MODULES 
   • Retrieve the continuous memory DTCs.
   • Is DTC U0138:xx or U0439:xx set in 1 or more modules in addition to the ABS module? 

   Yes	No
   Go to  BM7.	Go to  BM8.

7. BM7: CHECK FOR CORRECT ATCM OPERATION 
   • Ignition OFF.
   • ABS Module connector disconnected. (C135)
   • ATCM connector disconnected.
   • 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
   • ATCM connector connected. Make sure the connector seats and latches correctly.
   • ABS Module connector connected. (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	No
   INSTALL a new ATCM. 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 services articles address this concern, INSTALL a new ATCM. REFER to the Four-Wheel Drive Systems article.	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. BM8: CHECK FOR CORRECT ABS MODULE OPERATION 
   • Ignition OFF.
   • ABS Module connector disconnected. (C135)
   • ATCM connector disconnected.
   • 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
   • ATCM connector connected. Make sure the connector seats and latches correctly.
   • ABS Module connector connected. (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

   No

   INSTALL a new ABS module. 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 services articles address this concern, INSTALL a new ABS module. REFER to the Anti-Lock Brake System (ABS) and Stability Control article. ORDER a replacement ABS module and INCLUDE the RVC form. If this is a Ford repair, INCLUDE the RVC on the warranty claim form.

   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.