Possible Causes
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2021 Lincoln Corsair, 2021 Ford Transit-350 HD, 2021 Ford Transit-350, 2021 Ford Transit-250, and 2021 Ford Transit-150. However, it is still accessible from the selected car via links, so may be relevant.
- Tire Pressure
- Incorrect or mismatched tire
- Wiring, terminals or connectors
- Wheel bearing
- Wheel speed sensor encoder ring
- Wheel speed sensor
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 AND PIN DESCRIPTION
| Circuit | Pin |
|---|---|
| LF WSS HI (Left Front Wheel Speed Sensor High) - VCA03 | 1 (VIOLET/WHITE) |
| LF WSS LO (Left Front Wheel Speed Sensor Low) - RCA17 | 2 (YELLOW) |
Harness Side
CIRCUIT AND PIN DESCRIPTION
| Circuit | Pin |
|---|---|
| RF WSS HI (Right Front Wheel Speed Sensor HI) - VCA05 | 1 (GRAY/VIOLET) |
| RF WSS LO (Right Front Wheel Speed Sensor Low) - RCA19 | 2 (VIOLET) |
Harness Side
CIRCUIT AND PIN DESCRIPTION
| Circuit | Pin |
|---|---|
| LR WSS HI (Left Rear Wheel Speed Sensor High) - VCA04 | 1 (BLUE/ORANGE) |
| LR WSS LO (Left Rear Wheel Speed Sensor Low) - RCA18 | 2 (BROWN/GREEN) |
Harness Side
CIRCUIT AND PIN DESCRIPTION
| Circuit | Pin |
|---|---|
| RR WSS HI (Right Rear Wheel Speed Sensor High) - VCA06 | 1 (WHITE/ORANGE) |
| RR WSS LO (Right Rear Wheel Speed Sensor Low) - RCA20 | 2 (BROWN) |
- B1: Check For ABS Module DTCs
- Ignition ON.
- Using a diagnostic scan tool, carry out the ABS module self-test.
- Is DTC C003x:01, C003x:11, C003x:12, C003x:14 or C1A95:01 present?
Yes No For DTC C0031:01, C0031:11, C0031:12, C0031:14, C0032:11, C0034:01, C0034:11, C0034:12, C0034:14, C0035:11 or C1A95:01, GO to Pinpoint Test M.
For DTC C0037:01, C0037:11, C0037:12, C0037:14, C0038:11, C003A:01, C003A:11, C003A:12, C003A:14 or C003B:11, GO to Pinpoint Test N.Go to B2. - B2: Check The Tires Size And Pressure
- Ignition OFF.
- Verify all the tires and wheels are the same size and the tire size and inflation pressures are correct as indicated on the VC label.
- Are the tires and wheels OK?
Yes No Go to B3. INSTALL the correct size tire or wheel or ADJUST tire pressure as necessary. - B3: Check The Wheel Speed Sensor And Electrical Connector
- With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to the Jacking and Lifting article.
- Disconnect the suspect wheel speed sensor electrical connector.
- Using a good light source, inspect the wheel speed sensor and 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
- water intrusion - clean and dry the connector, install a new connector as necessary
- Inspect the wheel speed sensor and harness for abrasions, broken connector tabs or water intrusion.
- Are the wheel speed sensor and harness OK?
Yes No Go to B4. INSTALL a new wheel speed sensor for the one in question. REFER to FRONT WHEEL SPEED SENSOR , or Refer to REAR WHEEL SPEED SENSOR . - B4: Inspect The Wheel Speed Sensor Mounting
- Inspect the suspect wheel speed sensor and fastener for looseness.
- Inspect the suspect wheel speed sensor installation.
- Is the wheel speed sensor installed correctly and is the wheel speed sensor fastener tight?
Yes No Go to B5. INSTALL or TIGHTEN the wheel speed sensor fastener to specification. Refer to FRONT WHEEL SPEED SENSOR , or Refer to REAR WHEEL SPEED SENSOR . - B5: Check The Front And Rear Encoders For Damage NOTE: It may be necessary to remove the brake disc to thoroughly inspect the front wheel speed encoder.NOTE: It may be necessary to remove the rear axle shaft to thoroughly inspect the rear wheel speed encoder. It may be necessary to remove the rear axle shaft to thoroughly inspect the rear wheel speed encoder.
- Remove the front brake disc. Refer to FRONT BRAKE DISC
- Inspect the suspect front wheel speed sensor encoder for signs of damage, deformation and missing teeth.
- Inspect the suspect front wheel bearing for abnormal wear or roughness and for deformation or contamination of the seal and encoder.
- Remove the rear axle shaft. Refer to AXLE SHAFT - Ford 8.8 Inch Ring Gear
- Refer to AXLE SHAFT - Ford 9.75 Inch Ring Gear
Yes No Go to B6. For the front wheel hub, INSTALL a new wheel hub and bearing as necessary. REFER to the appropriate procedure in the FRONT WHEEL BEARING AND WHEEL HUB - AWD and/or FRONT WHEEL BEARING AND WHEEL HUB - 4WD .
For the rear wheel hub, INSTALL a new wheel hub and bearing as necessary. REFER to the appropriate procedure in the Rear Suspension article. - B6: Check The Wheel Speed Sensor Circuits For An Open
- 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 Module connector disconnected. C135 .
- Left Front Wheel Speed Sensor. C150 .
- Right Front Wheel Speed Sensor. C160 .
- Left Rear Wheel Speed Sensor. C440 .
- Right Rear Wheel Speed Sensor. C426 .
- For the left front wheel speed sensor, measure the resistance between:
Positive Lead Measurement / Action Negative Lead C135 Pin 41 Ω C150 Pin 1 C135 Pin 42 Ω C150 Pin 2 - For the right front wheel speed sensor, measure the resistance between:
Positive Lead Measurement / Action Negative Lead C135 Pin 40 Ω C160 Pin 1 C135 Pin 39 Ω C160 Pin 2 - For the left rear wheel speed sensor, measure the resistance between:
Positive Lead Measurement / Action Negative Lead C135 Pin 37 Ω C440 Pin 1 C135 Pin 38 Ω C440 Pin 2 - For the right wheel speed sensor, measure the resistance between:
Positive Lead Measurement / Action Negative Lead C135 Pin 36 Ω C426 Pin 1 C135 Pin 35 Ω C426 Pin 2 - Is the resistance less than 3 ohms?
Yes No Go to B7. REPAIR the affected connectors or terminals. Refer to the appropriate for schematic and connector information. - Put the ABS module in sleep mode by performing the following steps:
- B7: Check For Returning DTCs
- ABS Module connector connected.
- Left Front Wheel Speed Sensor connected. C150
- Right Front Wheel Speed Sensor connected. C160
- Left Rear Wheel Speed Sensor connected. C440
- Right Rear Wheel Speed Sensor connected. C426
- Ignition ON.
- Clear the ABS DTCs.
- Test drive the vehicle under normal driving conditions above 20 km/h (12 mph).
- Carry out the ABS self-test.
Are any of the Diagnostic Trouble Codes (DTCs) shown in the DTC Fault Trigger Conditions Table present?
Yes No Go to B8. 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. - B8: Verify All Wiring Connections
- Ignition OFF.
- 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 Module connector disconnected. C135 .
- Left Front Wheel Speed Sensor disconnected. C150 .
- Right Front Wheel Speed Sensor disconnected. C160 .
- Left Rear Wheel Speed Sensor disconnected. C440 .
- Right Rear Wheel Speed Sensor disconnected. C426 .
- 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 INSTALL a new Wheel Speed Sensor.
REFER to FRONT WHEEL SPEED SENSOR .
Refer to REAR WHEEL SPEED SENSOR .REPAIR the affected connectors or terminals.
REFER to CONNECTOR REPAIR PROCEDURES for schematic and connector information.