C107B

C107B-WHEEL SPEED COMPARATIVE PERFORMANCE

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

- When Monitored:
With the ignition on.

- Set Condition:
When one or more 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.





1. CHECK FOR DTC C107B-WHEEL SPEED COMPARATIVE PERFORMANCE

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

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

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

Does the scan tool display: C107B-WHEEL SPEED COMPARATIVE PERFORMANCE?

Yes

- Go To 2

No

- Perform the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test.

2. CHECK WHEEL SPEED SENSOR SIGNALS
1. Turn the ignition on.
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 m.p.h.).

Is one or more WSS speeds showing 0 km/h (0 m.p.h.) or not matching other wheel speeds?

Yes

- Go To 3

No

- Perform the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test.

3. CHECK WSS LOOSENESS, INSPECT SIGNAL,SUPPLY 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, each WSS, and each WSS harness connector.
3. Inspect each WSS for looseness and not properly fastened.
4. Inspect each WSS Signal and WSS Supply circuits between each WSS and Anti-Lock Brake Module for damage.

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

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 4

4. CHECK BRAKE SYSTEM
1. Turn the ignition off.
2. Check the brake fluid level.
3. Check for trapped air in brake lines.
4. Inspect for brake fluid leakage on vehicle.
5. Inspect for loose mounted brake hardware.

Are any of the above conditions present?

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 5

5. CHECK EACH TONE WHEEL FOR DAMAGE
1. Turn the ignition off.
2. Inspect each Tone Wheel for damage, missing teeth, cracks, or looseness.

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

Is the Tone Wheels damaged?

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 6

6. ANTI-LOCK BRAKE MODULE - INTERNAL FAULT
1. Turn the ignition off.
2. Replace WSS in question and perform ABS VERIFICATION TEST ABS Verification Test.
3. With the scan tool, erase DTCs.
4. Road test the vehicle over 40 km/h (25 m.p.h.).
5. Turn the ignition on.
6. With the scan tool, read DTCs

Did the DTC C107B-WHEEL SPEED COMPARATIVE PERFORMANCE reset?

Yes

- Replace the Anti-Lock Brake Module.
- Perform ABS VERIFICATION TEST ABS Verification Test.

No

- Test Complete.