Diagnostic Routine B

Diagnostic Routine B

Diagnostic Overview

Wheel Speed Sensor Erratic Signal DTCs

Normal Operation and Fault Conditions

The wheel speed sensor utilizes the magnetic strip on the wheel bearing to generate a square wave signal proportional to wheel speed that is sent to the ABS (Anti-Lock Brake System) module. The wheel bearing, magnetic strip and wheel speed sensor must be undamaged and free from any contamination to produce a clean signal for use by the ABS (Anti-Lock Brake System) module. Also, all 4 tires and wheels must be of the same, manufacturer recommended size for the wheel speed sensor to generate an accurate wheel speed.

DTC (Diagnostic Trouble Code) Fault Trigger Conditions






Pinpoint Test

1. CHECK THE DTCs (Diagnostic Trouble Codes) FROM THE ABS (Anti-Lock Brake System) MODULE SELF-TEST

1. Ignition ON.

2. Using a scan tool, carry out the ABS (Anti-Lock Brake System) module self-test.

Is DTC (Diagnostic Trouble Code) C0031:01; C0034:01; C0037:01 and/or C003A:01 present?






2. CHECK THE TIRES SIZE AND PRESSURE

1. Verify that all tires and wheels are the same size and that the tire size and inflation pressures are correct as indicated on the VC (Vehicle Certification) label.

Are the wheels and tires OK?






3. CHECK THE WHEEL SPEED SENSOR AND HARNESS FOR DAMAGE

1. Ignition OFF.

2. With the vehicle in NEUTRAL, position it on a hoist. REFER to Lifting Points .

3. NOTE: Examine the wheel speed sensor wire carefully with a good light source. Failure to verify damage in the wheel speed sensor wire can lead to unnecessary installation of a new component.
Inspect the wheel speed sensor and harness for abrasion, broken connector tabs or water intrusion.

Is the wheel speed sensor and harness OK?






4. INSPECT THE WHEEL SPEED SENSOR MOUNTING

1. Inspect the wheel speed sensor and fastener for looseness.

Are the wheel speed sensor and fastener tight?






5. CHECK THE WHEEL BEARING MAGNETIC STRIPS FOR DAMAGE

1. Inspect the wheel bearings for abnormal wear or roughness and for deformation or contamination of the seal and magnetic strip.

Are the wheel bearing(s) OK?






6. MONITOR THE ABS (Anti-Lock Brake System) MODULE WHEEL SPEED SENSOR PIDs (Parameter Identifications)

1. Ignition ON.

2. Using a scan tool, monitor the PIDs (Parameter Identifications) while an assistant drives the vehicle at a speed greater than 20 km/h (12.4 mph).

- Left front wheel speed sensor (LF_WSPD)
- Right front wheel speed sensor (RF_WSPD)
- Left rear wheel speed sensor (LR_WSPD)
- Right rear wheel speed sensor (RR_WSPD)

Are the wheel speed PIDs (Parameter Identifications) within 5 km/h (3.1 mph) of each other and the vehicle speed as indicated on the speedometer?






7. CHECK THE HARNESS AND CONNECTORS

1. Disconnect the suspect wheel speed sensor electrical connector.

2. Disconnect ABS (Anti-Lock Brake System) Module electrical connector.

3. Inspect the connectors (including any in-line connectors) for:

- corrosion
- loose or spread terminals
- loose or frayed wire connections at terminals

Were any concerns found?






8. CHECK FOR CORRECT ABS (Anti-Lock Brake System) MODULE OPERATION

1. Ignition OFF.

2. Disconnect and inspect the ABS (Anti-Lock Brake System) Module electrical connector.

3. Repair:

- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

4. Connect the ABS (Anti-Lock Brake System) Module electrical connector. Make sure it seats and latches correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?