Possible Causes

• Network communication concern
• VDM
• ABS module

Fig 1: Antilock Braking System Module Connector (C135)

Courtesy of FORD MOTOR COMPANY

Harness Side

1. BR1: CHECK THE VDM 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 VDM pass the Network Test? 

     Yes	No
     Go to  BR2.	DIAGNOSE the scan tool does not communicate with the VDM. Refer to Module Communications Network article.

2. BR2: RECHECK THE ABS MODULE FOR THE LOST COMMUNICATION DTC 
   • Clear the ABS DTCs.
   • Ignition OFF.
   • Ignition ON, engine OFF.
   • Carry out the ABS self-test.
   • Is DTC U0122:xx still present? 

     Yes	No
     Go to  BR3.	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. BR3: REVIEW THE ABS MODULE SELF-TEST FOR VOLTAGE-RELATED DTCS 
   • Review the results from the ABS module self-test.
   • Is DTC U3003:16 or U3003:17 present? 

     Yes	No
     For DTC U3003:17, Go to PINPOINT TEST A . For DTC U3003:16, Go to PINPOINT TEST F .	Go to  BR4.

4. BR4: CHECK FOR VDM DTCS 
   • Carry out the VDM self-test.
   • Are any DTCs present? 

     Yes	No
     DIAGNOSE the VDM DTC. REFER to Vehicle Dynamic Suspension article.	Go to  BR5.

5. BR5: 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 VDM 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  BR6.	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

6. BR6: CHECK FOR COMMUNICATION DTCS IN OTHER MODULES 
   • Ignition ON, engine OFF.
   • Retrieve the continuous memory DTCs.
   • Is DTC U0122:xx set in 1 or more modules in addition to the ABS module? 

     Yes	No
     Go to  BR7.	Go to  BR8.

7. BR7: VERIFY PCM OPERATION 
   • Ignition OFF.
   • VDM_A connector disconnected.
   • VDM_B connector disconnected.
   • ABS Module connector disconnected. (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
   • ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
   • VDM_B connector connected. Make sure the connector seats and latches correctly.
   • VDM_A connector connected. 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 VDM. CHECK OASIS for any service articles: TSB, GSB (general service bulletin), SSM (special service message) or FSA (Field Service Action). 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 VDM. REFER to Vehicle Dynamic Suspension article.	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.

8. BR8: VERIFY ABS MODULE OPERATION 
   • Ignition OFF.
   • ABS Module connector disconnected. (C135)
   • VDM_A connector disconnected.
   • VDM_B 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
   • VDM_A connector connected. Make sure the connector seats and latches correctly.
   • VDM_B 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 service articles: TSB, GSB (general service bulletin), SSM (special service message) or FSA (Field Service Action). 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 ABS module. REFER to Anti-Lock Brake System (ABS) and Stability Control article. ORDER a replacement ABS module and INCLUDE the RVC on the form. If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.

     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.