Possible Causes

• Incorrect sensor input
• Stuck valve
• ABS module
• ABS module and HCU assembly

Fig 1: Antilock Braking System Module Connector (C135)

Courtesy of FORD MOTOR COMPANY

Harness Side

1. Y1: GUIDED DIAGNOSTIC QUESTION 
   • This step is for vehicles equipped with an EPB system.
   • Were you sent here from diagnostics in Parking Brake and Actuation article? 

     Yes	No
     Go to  Y4.	Go to  Y2.

2. Y2: RECHECK THE ABS MODULE FOR DTCS 
   • Ignition ON, engine OFF.
   • Clear the ABS DTCs.
   • Ignition OFF.
   • Ignition ON, engine OFF.
   • Carry out the ABS self-test.
   • Record the ABS module DTCs.
   • Is DTC C1A99:xx, U2007:1B or U2007:49 present and active in the ABS module? 

     Yes	No
     Go to  Y5.	Go to  Y3.

3. Y3: VERIFY THE ABS MODULE TO HCU FASTENERS 
   • Ignition OFF.
   • Verify all ABS module-to-HCU fasteners are tightened to their correct torque specifications. Refer to Anti-Lock Brake System (ABS) and Stability Control article.
   • Are the fasteners tightened to their correct torque specifications? 

     Yes	No
     Go to  Y4.	TIGHTEN all ABS module fasteners to their correct torque specifications. Go to  Y4.

4. Y4: CHECK FOR CORRECT ABS MODULE OPERATION 
   • Ignition OFF.
     NOTE: The battery must be removed to access the ABS module electrical connector.
   • Remove the battery. Refer to the appropriate procedure in Battery, Mounting and Cables article
   • ABS Module connector disconnected. (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
   • ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
   • Install the battery. Refer to the appropriate procedure in Battery, Mounting and Cables article
   • Operate the system and determine if 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, 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 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.

5. Y5: CHECK FOR CORRECT ABS OPERATION 
   • Ignition OFF.
     NOTE: The battery must be removed to access the ABS module electrical connector.
   • Remove the battery. Refer to the appropriate procedure in Battery, Mounting and Cables article.
   • ABS Module connector disconnected. (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
   • ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
   • Install the battery. Refer to the appropriate procedure in Battery, Mounting and Cables article.
   • Operate the system and determine if the concern is still present.
   • Is the concern still present? 

     Yes

     No

     INSTALL a new HCU. 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 ABS module and HCU assembly. REFER to Anti-Lock Brake System (ABS) and Stability Control article. ORDER a replacement ABS module and HCU assembly. 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.