C102A

C102A - LEFT REAR WHEEL SPEED COMPARATIVE PERFORMANCE






For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on.

- Set Condition:
When the Left Rear WSS reading is different from the readings received from the other WSS's. The Anti-Lock Brake Module compares WSS readings from side-to-side on an axle and front-to-rear.






DIAGNOSTIC TEST

1. CHECK FOR DTC C102A - LEFT REAR WHEEL SPEED COMPARATIVE PERFORMANCE

Note: This DTC must be active for the results of this test to be valid.






Note: The Anti-Lock Brake Module must sense ALL 4 wheels at 12 km/h (7.5 mph) before it will extinguish the ABS indicators.

1. Turn the ignition on.
2. With the scan tool, record and erase DTC's.
3. Cycle the ignition switch from off to on.
4. With the scan tool, read DTC's.

Does the scan tool display: C102A - LEFT REAR WHEEL SPEED COMPARATIVE PERFORMANCE and C1020 - LEFT REAR WHEEL SPEED SENSOR CIRCUIT?

Yes
- Refer to C1020-Left Rear Wheel Speed Sensor Circuit for the related symptom(s). Refer to C1020
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test


No
- Go To 2.

2. CHECK WHEEL SPEED SENSOR SIGNALS






1. Turn the ignition off.
2. With the scan tool, monitor ALL the WSS speeds while an assistant drives the vehicle.
3. Slowly accelerate as straight as possible from a stop to 40 km/h (25 mph).

Is the Left Rear WSS Speed showing 0 km/h (0 mph) or not matching other wheel speeds?

Yes
- Go To 3.

No
- Refer to the Intermittent Condition Diagnostic Procedure.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test



3. CHECK LEFT REAR WSS LOOSENESS, INSPECT B3, B4 CIRCUITS/CONNECTORS/TERMINALS FOR DAMAGE






Note: Check all terminals for broken, bent, pushed out, or corroded terminals.

1. Turn the ignition off.
2. Inspect the Anti-Lock Brake Module harness connector, Left Rear WSS, and Left Rear WSS harness connector.
3. Inspect the Left Rear WSS for looseness and not properly fastened.
4. Inspect the (B3) Left Rear WSS Signal and (B4) Left Rear WSS Supply circuits between the Left Rear WSS and Anti-Lock Brake Module for damage.

Is the Left Rear WSS loose or any of the wiring/connectors/terminals damaged?

Yes
- Repair as necessary.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test

No
- Go To 4.

4. CHECK LEFT REAR TIRE PRESSURE/INSPECT ALL TIRES

1. Turn the ignition off.
2. Check and adjust the Left Rear Tire pressure.
3. Check and adjust all other tire pressures.
4. Inspect for mismatched tires on vehicle.

Is the Left Rear Tire improperly inflated or mismatched tires on vehicle?

Yes
- Repair as necessary.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test

No
- Go To 5.

5. CHECK LEFT REAR TONE WHEEL FOR DAMAGE

1. Turn the ignition off.
2. Inspect the Left Rear Tone Wheel for damage, missing teeth, cracks, or looseness.

Note: The Tone Wheel teeth should be perfectly square, not bent, or nicked.

Is the Left Rear Tone Wheel damaged?

Yes
- Repair as necessary.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test

No
- Go To 6.

6. CHECK LEFT REAR BRAKE HARDWARE DAMAGE

1. Turn the ignition off.
2. Visually inspect the Left Rear brake linings for contamination or overheating. Check for dragging, bent, or seized components/hardware.

Is any brake lining, component, or hardware damaged?

Yes
- Repair as necessary.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test

No
- Go To 7.

7. ANTI-LOCK BRAKE MODULE - INTERNAL FAULT






1. Turn the ignition off.
2. Replace the Left Rear WSS.
3. With the scan tool, erase DTC's.
4. Road test the vehicle over 40 km/h (25 mph).
5. Turn the ignition on.
6. With the scan tool, read DTC's.

Did the DTC C102A - LEFT REAR WHEEL SPEED COMPARATIVE PERFORMANCE reset?

Yes
- Replace the Anti-Lock Brake Module.
- Perform ABS Verification Test-VER 1. Refer to ABS Verification Test

No
- Test Complete.