Visual Inspection and Diagnostic Pre-checks
WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
- Make sure the wheel speed sensor harness is routed correctly and is undamaged.
- Make sure the wheel speed sensor electrical connector is free from any corrosion or other contaminants.
NOTE:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
Harness Side
| Circuit | Pin |
|---|---|
| LR WSS LO (Left Rear Wheel Speed Sensor Low) - RCA18 | 18 (BROWN/GREEN) |
| LR WSS HI (Left Rear Wheel Speed Sensor High) - VCA04 | 31 (BLUE/ORANGE) |
| RR WSS LO (Right Rear Wheel Speed Sensor Low) - RCA20 | 29 (BROWN) |
| RR WSS HI (Right Rear Wheel Speed Sensor High) - VCA06 | 17 (WHITE/ORANGE) |
Harness Side
| Circuit | Pin |
|---|---|
| LR WSS LO (Left Rear Wheel Speed Sensor Low) - RCA18 | 2 (BROWN/GREEN) |
| LR WSS HI (Left Rear Wheel Speed Sensor High) - VCA04 | 1 (BLUE/ORANGE) |
Harness Side
| Circuit | Pin |
|---|---|
| RR WSS LO (Right Rear Wheel Speed Sensor Low) - RCA20 | 2 (BROWN) |
| RR WSS HI (Right Rear Wheel Speed Sensor High) - VCA06 | 1 (WHITE/ORANGE) |
- N1: CHECK FOR FAULT REPEATABILITY
- Ignition ON, engine OFF.
- Clear the ABS DTCs.
- Ignition OFF.
- Ignition ON, engine OFF.
Carry out the ABS self-test.
- Is one or more of the DTCs shown in the ABS DTC Fault Trigger Conditions table present?
Yes No For failure type byte 01 (General Electrical Failure), 12 (Circuit Short to Ground) or 15 (Circuit Short to Battery or Open Circuit), Go to N2.
For failure type byte 11 (Circuit Short to Ground) or 14 (Circuit Short to Ground or Open Circuit), Go to N3.The system is operating correctly at this time.
INSPECT both rear wheel speed sensor electrical connectors and the ABS module electrical connector.
REPAIR or CLEAN the connector as necessary.
ADDRESS the root cause of any connector or pin issues. - N2: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO BATTERY VOLTAGE
- Ignition OFF.
- ABS Module connector disconnected. (C135)
- Disconnect the suspect wheel speed sensor.
- Ignition ON, engine OFF.
- For the left rear wheel speed sensor:
- Measure the voltage between:
(+) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side (-) LR WSS LO - RCA18 (BROWN/GREEN) - Pin 2 Ground LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 1 Ground - For the right rear wheel speed sensor:
- Measure the voltage between:
(+) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side (-) RR WSS LO - RCA20 (BROWN) - Pin 2 Ground RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 1 Ground - Is any voltage present?
Yes No REPAIR the circuit. Go to N3. - N3: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- ABS Module connector disconnected. (C135)
- Disconnect the suspect wheel speed sensor (if not previously disconnected).
- For the left rear wheel speed sensor:
- Measure the resistance between:
(+) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side (-) LR WSS LO - RCA18 (BROWN/GREEN) - Pin 2 Ground LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 1 Ground - For the right rear wheel speed sensor:
- Measure the resistance between:
(+) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side (-) RR WSS LO - RCA20 (BROWN) - Pin 2 Ground RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 1 Ground - Are the resistances greater than 100, 000 ohms?
Yes No Go to N4. REPAIR the circuit. - N4: CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS
- For the left rear wheel speed sensor:
- Measure the resistance between:
(+) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side (-) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 1 LR WSS LO - RCA18 - Pin 2 - For the right rear wheel speed sensor:
- Measure the resistance between:
(+) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side (-) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 1 RR WSS LO - RCA20 - Pin 2 - Is the resistance greater than 100, 000 ohms?
Yes No Go to N5. REPAIR the circuit. - N5: CHECK THE WHEEL SPEED CIRCUITS FOR AN OPEN
- For the left rear wheel speed sensor:
- Measure the resistance between:
(+) ABS Module (C135) Connector, Harness Side (-) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side LR WSS LO - RCA18 (BROWN/GREEN) - Pin 18 LR WSS LO - RCA18 - Pin 2 LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 31 LR WSS HI - VCA04 - Pin 1 - For the right rear wheel speed sensor:
- Measure the resistance between:
(+) ABS Module (C135) Connector, Harness Side (-) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side RR WSS LO - RCA20 (BROWN) - Pin 29 RR WSS LO - RCA20 - Pin 2 RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 17 RR WSS HI - VCA06 - Pin 1 - Are the resistances less than 3 ohms?
Yes No Go to N6. REPAIR the circuit. - N6: CHECK THE ABS MODULE OUTPUT
- ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
- Ignition ON, engine OFF.
- For the left rear wheel speed sensor:
- Measure the voltage between:
(+) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side (-) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 1 LR WSS LO - RCA18 - Pin 2 - For the right rear wheel speed sensor:
- Measure the voltage between:
(+) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side (-) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 1 RR WSS LO - RCA20 - Pin 2 - Is the voltage greater 10 volts?
Yes No INSTALL a new WSS.
REFER to the Anti-Lock Brake System (ABS) and Stability Control article.Go to N7. - N7: VERIFY ALL WIRING CONNECTIONS
- Ignition OFF.
- 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
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
Yes No Go to N8. REPAIR the affected connectors or terminals. Refer to the OEM Connector Repair Procedures article for schematic and connector information. - N8: CHECK FOR APPLICABLE SERVICE ARTICLES
- CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA.
- Do any applicable service articles exist?
Yes No DISCONTINUE this test and FOLLOW the service article instructions. Go to N9. - N9: CHECK FOR CORRECT ABS MODULE OPERATION
- ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
- Connect the suspect wheel speed sensor electrical connector. 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 ABS module.
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 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. - N10: CHECK FOR CORRECT ABS OPERATION
- ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
- Connect the suspect wheel speed sensor electrical connector. Make sure the connector seats and latches correctly.
- Install the battery. Refer to the appropriate procedure in the 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.
INSTALL a new ABS module and HCU assembly.
REFER to the 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.