4000 - 4999: 4575

4575-WHEEL SPEED SENSOR - INCORRECT DIRECTION

For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on.

- Set Condition:
When the Wheel Speed Sensor (WSS) Signal reading is different from the readings received from the other WSS's at a vehicle speed above 40 km/h (20 mph). 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 4575-WHEEL SPEED SENSOR - INCORRECT DIRECTION
NOTE: Check vehicle history, if sensor in question has been replaced verify correct wheel speed sensor was installed.

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

Turn the ignition on.
With the scan tool, record and erase DTCs.
Road test the vehicle over 40 km/h (20 mph).

NOTE: Vehicle must be driven above 40 km/h (20 mph) for set conditions to be met.

With the scan tool, read DTCs.
Does the scan tool display: 4575-WHEEL SPEED SENSOR - INCORRECT DIRECTION active?

Yes

- Go To 3

No

- Go To 2

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 (20 mph).
Is the WSS speed showing 0 km/h (0 mph) or not matching other wheels or showing erratic behavior?

Yes

- Go To 3

No

- The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
- Refer to the ABS-INTERMITTENT CONDITION TEST.


3. CHECK FOR IMPROPER TIRE PRESSURE/MISMATCHED TIRES
Turn the ignition off.
Check and adjust the Tire pressure.
Check and adjust all other tire pressures.
Inspect for mismatched tires on vehicle.
Is the Tire improperly inflated or mismatched tires on vehicle?

Yes

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

No

- Go To 4

4. CHECK WSS LOOSENESS, INSPECT CIRCUITS/TERMINALS FOR DAMAGE

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

Inspect the Anti-Lock Brake Module harness connector, WSS, and WSS harness connector.
Inspect the WSS for looseness, excessive corrosion and not properly fastened.
Inspect the WSS Signal(-) and WSS Supply(+) circuits between the WSS and Anti-Lock Brake Module for damage.
Is the WSS loose or any of the wiring/connectors/terminals damaged?

Yes

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

No

- Go To 5

5. CHECK WHEEL SPEED SENSOR FOR DAMAGE
Remove the Wheel Speed Sensor
Inspect the Wheel Speed Sensor face for damage.
Is the Wheel Speed Sensor damaged?

Yes

- Replace sensor and hub assembly.
- Perform ABS VERIFICATION TEST. Verification Tests.

No

- Go To 6

6. CHECK TONE WHEEL/BEARING FOR DAMAGE
Inspect the Tone Wheel/Bearing for damage, missing teeth, cracks, corrosion or looseness.

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

Is the Tone Wheel/Bearing damaged?

Yes

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

No

- Go To 7

7. WHEEL SPEED SENSOR
Replace the Wheel Speed Sensor.
Perform ABS VERIFICATION TEST. Verification Tests.
Road test the vehicle over 40 km/h (20 mph).

NOTE: Vehicle must be driven above 40 km/h (20 mph) for set conditions to be met.

With the scan tool, read ABS DTCs.
Did DTC 4575-WHEEL SPEED SENSOR - INCORRECT DIRECTION reset?

Yes

- Replace the Anti-Lock Brakes Module.
- Perform ABS VERIFICATION TEST. Verification Tests.

No

- Test Complete.