Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Inspect the tires for improper air pressure and or mismatched tires before continuing, repair as necessary.

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, read ABS DTCs and record on the repair order.
3. With the scan tool, erase ABS DTCs.
  CAUTION:
  Make sure brake capability is available before road testing.
4. Road test the vehicle over 40 km/h (25 mph).
5. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
CHECK WHEEL SPEED SENSOR SIGNALS
1. Turn the ignition on.
2. With the scan tool, monitor and graph ALL the Wheel Speed Sensors speeds and compare.
3. Slowly accelerate as straight as possible from a stop to 40 km/h (25 mph).
  Is one or more of the WSS speeds showing 0 km/h (0 mph) or not matching the other WSS speeds?
  
  Yes
  - Go To 3
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
INSPECT WHEEL SPEED SENSOR FOR DAMAGE
NOTE:
Check all terminals for broken, bent, pushed out, or corroded terminals.
1. Turn the ignition off.
2. Inspect each WSS for looseness and or not properly fastened.
  Are any WSS loose or any of the wiring/connectors/terminals damaged?
  
  Yes
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
CHECK EACH HUB AND WHEEL BEARING FOR DAMAGE
1. Turn the ignition off.
2. Inspect each Hub and Wheel Bearing for damage, corrosion, cracks, looseness, or improper installation.
  Are any of the Hub and or Wheel Bearings damaged?
  
  Yes
  - Replace the Hub and Wheel Bearing in accordance with the Service Information. Refer to HUB AND BEARING, REMOVAL or HUB AND BEARING, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 5
WHEEL SPEED SENSOR (WSS)
1. Replace the Wheel Speed Sensor in accordance with the Service Information. Refer to SENSOR, WHEEL SPEED, FRONT, REMOVAL or SENSOR, WHEEL SPEED, REAR, REMOVAL .
2. Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
3. With the scan tool, monitor and graph ALL the Wheel Speed Sensors speeds and compare.
4. Slowly accelerate as straight as possible from a stop to 40 km/h (25 mph).
5. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM (ABS), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Test complete.