Visual Inspection and Diagnostic Pre-checks

WARNING: This page is about a different car, the 2020 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

Make sure the vehicle battery terminals and cables are free of any corrosion and other contaminants.
Make sure the vehicle battery terminals are tightened to their correct torque specifications.
Make sure BCM-C fuses 28 (40A) and 29 (60A), and the fuse sockets, are OK.

NOTE: The ABS module must enter sleep mode before disconnecting the electrical connector or additional DTCs can be set.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Fig 1: Anti-Lock Brake System-A (ABS-A) Module Connector - C135A

Courtesy of FORD MOTOR CO.

Harness Side

Circuit	Pin
LOGICGND - GD191	1 (BLACK/GREEN)
VLVPWR (Valve Power) - SBB28	14 (GREEN/RED)

Fig 2: Anti-Lock Brake System-B (ABS-B) Module Connector - C135B

Courtesy of FORD MOTOR CO.

Harness Side

Circuit	Pin
PUMPGND - GD121	2 (BLACK/YELLOW)
PUMPPWR (Pump Power.) - SBB29	1 (GRAY/RED)

Fig 3: Body Control Module C-B (BCM-C-B) Connector - C1035B

Courtesy of FORD MOTOR CO.

Harness Side

Circuit

H1: CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM

Verify the vehicle battery and charging system are operating correctly. Refer to Inspection and Verification in Charging System Diagnosis and Testing, in the Charging System General Information article..

Are the battery and charging system operating correctly?

Yes	No
Go to H2.	FOLLOW the diagnostic repair directions as instructed in Charging System Diagnosis and Testing, in the Charging System General Information article..

H2: VERIFY ALL WIRING CONNECTIONS

NOTE: The ABS module must enter sleep mode before disconnecting the electrical connector or additional DTCs can be set.

Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
ABS_A Module connector disconnected. (C135A)
ABS_B Module connector disconnected. (C135B)
BCM-C_B connector disconnected. (C1035B)
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
Using a suitable mating terminal, check each connector terminal for deformed or enlarged contacts by comparing the mating terminal's fit between each of the following pins:
- C135A-1
- C135A-14
- C135B-1
- C135B-2
- C1035B-59

Are the connectors free of terminal corrosion, pushed-out terminals and spread terminals?

Yes	No
Go to H4.	REPAIR the affected terminal. Refer to the Connector Repair Procedures wiring diagrams, for schematic and connector information.

H3: CHECK PUMP MOTOR OPERATION

Ignition ON, engine OFF.
Access the ABS and control the PMP_MTR (MODE) PID.
Command the pump motor on and listen for the ABS pump motor to activate.

Does the ABS pump motor run for approximately 2 seconds when commanded on?

Yes	No
Go to H4.	Go to H7.

H4: CHECK FOR FAULT REPEATABILITY

ABS_A Module connector connected. (C135A) Make sure the connector seats and latches correctly.
ABS_B Module connector connected. (C135B) Make sure the connector seats and latches correctly.
BCM-C_B connector connected. (C1035B)
Ignition ON, engine OFF.
Clear the ABS DTCs.
Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
Ignition ON, engine OFF.
Test drive the vehicle at speeds greater than 20 km/h (12 mph).
Ignition OFF.
Ignition ON, engine OFF.
Carry out the ABS self-test.

Are any of the DTCs listed in the Fault Trigger Conditions Table present?

Yes	No
Go to H5.	The condition causing the concern is not present at this time. DISCONNECT and INSPECT the ABS module electrical connector. CLEAN or REPAIR the connector as necessary. ADDRESS the root cause of any connector or pin issues.

H5: CHECK THE ABS MODULE GROUND CIRCUIT FOR AN OPEN

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

NOTE: This step puts a load on the ABS module voltage supply circuit. If there are corroded or loose connections, loading the circuit may help show the fault. A 9006 or 9007 headlamp bulb is an effective load.

Ignition OFF.
ABS_A Module connector disconnected. (C135A)
Ignition ON, engine OFF.
Connect the load to a suitable, fused 12-volt power connection.
Connect the load to each circuit before taking the voltage measurement.

Measure the voltage between:

(+) ABS Module Connector, Harness Side	(-)
GND	Ground
LOGICGND	Ground

Measure the voltage between:

(+) ABS_B Module (C135B) Connector, Harness Side	(-)
PUMPGND - GD121 (BLACK/YELLOW) - Pin 2	Ground

Measure the voltage between:

(+) ABS_A Module (C135A) Connector, Component Side	(-)
LOGICGND - GD191 (BLACK/GREEN) - Pin 1	Ground

Is the voltage drop less than 0.5 volt?

H6: VERIFY ABS MODULE GROUND CONNECTIONS

NOTE: Refer to the Grounds wiring diagrams, for ground connection information.

Position aside the BCM-C.
Disconnect all ABS module ground joint connections. Refer to the Grounds wiring diagrams, for ground information.
- Discard the bolts.
Inspect the ground joint connections for:
- Rust
- Corrosion
- Other foreign material
- Cross-threaded fasteners
NOTE: Do not remove any paint from the body as the ground path conduction is through the bolt threads.
Clean or repair the ground joint connections as necessary.
Connect all ABS module ground joint connections. Make sure the connections are clean, tight and not cross threaded.
- Install new bolts and tighten to 12 Nm (106 lb-in).
Measure the resistance between:
- Each ground joint bolt.
- The battery negative cable terminal.

Are the measured resistances less than 1 Ohm?

Yes	No
Go to H7.	CLEAN or REPAIR the ground joint connection. Go to H7.

H7: CHECK THE PUMP MOTOR VOLTAGE SUPPLY TO THE ABS MODULE

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

NOTE: VERIFY BCM-C fuses 28 (40A) and 29 (60A) are OK. If not OK, REFER to the the OEM Electrical Wiring Diagram Introduction article to identify the possible causes of the circuit short.

Ignition ON, engine OFF.

Measure the voltage between:

(+) Vehicle Battery	(-) Vehicle Battery
Positive terminal	Negative terminal

Record the measured battery voltage.
Connect the load to a suitable ground connection.
Connect the load to each circuit before taking the voltage measurement.

Measure the voltage between:

(+) ABS Module Connector, Harness Side	(-)
Motor B+	Ground

Measure the voltage between:

(+) ABS_B Module (C135B) Connector, Harness Side	(-)
PUMPPWR - SBB29 (GRAY/RED) - Pin 1	Ground

Measure the voltage between:

(+) ABS_A Module (C135A) Connector, Component Side	(-)
VLVPWR - SBB28 (GREEN/RED) - Pin 14	Ground

Is each voltage within 0.5 volt of the recorded battery voltage?

Yes	No
Go to H8.	REPAIR the circuit.

H8: VERIFY ALL WIRING CONNECTIONS
- 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
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
H9: CHECK FOR APPLICABLE SERVICE ARTICLES
- Check OASIS for any service articles: TSB, GSB, SSM or FSA.
- Do any applicable service articles exist?

H10: CHECK FOR CORRECT ABS MODULE AND HCU OPERATION

ABS Module connector connected. Make sure the connector seats and latches correctly.
Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new HCU. INSTALL a new HCU and ABS module assembly. REFER to the Anti-Lock Brake System (ABS) and Stability Control article. ORDER a replacement HCU and ABS module assembly 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.

H11: CHECK FOR CORRECT ABS OPERATION

ABS_A Module connector connected. (C135A) Make sure the connector seats and latches correctly.
ABS_B Module connector connected. (C135B) Make sure the connector seats and latches correctly.
Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new EBB assembly. The HCU and ABS module are a single assembly known as the EBB unit. INSTALL a new EBB unit (HCU and ABS module assembly). REFER to the Anti-Lock Brake System (ABS) and Stability Control article. ORDER a replacement EBB unit 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.