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

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.

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.

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.

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.

Yes

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.

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.

Yes

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.