Diagnostic Test
- VERIFY THE DTC IS ACTIVE NOTE:
If DTC C0031-1D is present, perform the appropriate diagnostics for this DTC before continuing with this diagnostic procedure.
- Turn the ignition on.
- With the scan tool, record and erase DTCs.CAUTION:
Make sure brake capability is available before road testing.
- Road test the vehicle over 40 km/h (25 mph).NOTE:
Vehicle must be driven above 40 km/h (25 mph) for set conditions to be met.
- With the scan tool, read DTCs.
Is the DTC active at this time?
Yes
- Go To 3
No
- Go To 2
- CHECK WHEEL SPEED SENSOR SIGNALS
- Turn the ignition on.
- With the scan tool, monitor and graph ALL the WSS speeds and compare graph while an assistant drives the vehicle.NOTE:
If graph shows periodic dropouts pay close attention to the tone wheel.
- Slowly accelerate as straight as possible from a stop to 40 km/h (25 mph).
Is the Left Front WSS speed showing 0 km/h (0 mph), not matching other wheels, or showing erratic behavior?
Yes
- Go To 3
No
- Perform the ABS INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
- CHECK LEFT FRONT WSS FOR LOOSENESS, INSPECT CIRCUITS/CONNECTORS/TERMINALS FOR DAMAGE NOTE:
Check all terminals for broken, bent, pushed out, or corroded terminals.
- Turn the ignition off to the lock position.
- Inspect the ABS Module harness connector and the Left Front WSS harness connector.
- Check the Left Front WSS for looseness, excessive corrosion and not properly fastened.
- Inspect the (B8) Left Front WSS Signal and (B9) Left Front WSS Supply circuits between the Left Front WSS and Anti-Lock Brake Module for damage.
Is the Left Front WSS loose or any of the wiring/connectors/terminals damaged?
Yes
- Repair as necessary.
- Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 4
- CHECK LEFT FRONT WHEEL SPEED SENSOR FOR DAMAGE
- Remove the Left Front Wheel Speed Sensor.
- Inspect the Wheel Speed Sensor for proper mounting.
- Inspect the Wheel Speed Sensor harness and connector.
- Inspect the Wheel Speed Sensor for excessive debris on the sensor.
Is the Left Front Wheel Speed Sensor damaged?
Yes
- Replace the Left Front Wheel Speed Sensor in accordance with the Service Information. Refer to SENSOR, WHEEL SPEED, FRONT, REMOVAL .
- Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 5
- CHECK LEFT FRONT WHEEL BEARING AND HUB OR ENCODER FOR DAMAGE
- Inspect the Left Front wheel bearing, hub and Encoder for excessive runout, clearance or damage.NOTE:
Refer to the appropriate service information, if necessary, for procedures or specifications.
Is the Left Front Wheel Bearing, Hub or Encoder Damaged?
Yes
- Replace the Hub and Wheel Bearing in accordance with the Service Information. Refer to HUB AND BEARING, REMOVAL .
- Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 6
- Inspect the Left Front wheel bearing, hub and Encoder for excessive runout, clearance or damage.
- LEFT FRONT WHEEL SPEED SENSOR
- Replace the Left Front Wheel Speed Sensor in accordance with the Service Information. Refer to SENSOR, WHEEL SPEED, FRONT, REMOVAL .
- Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Road test the vehicle over 40 km/h (25 mph).NOTE:
Vehicle must be driven above 40 km/h (25 mph) for set conditions to be met.
- With the scan tool, read ABS DTCs.
Does the DTC remain active?
Yes
- Replace the Anti-Lock Brakes Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
- Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Test Complete.