Diagnostic Test

CHECK FOR AN ACTIVE DTC
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.
  CAUTION:
  Make sure brake capability is available before road testing.
3. Road test the vehicle over 40 km/h (25 mph).
  NOTE:
  Vehicle must be driven above 40 km/h (25 mph) for two minutes before set conditions are met.
4. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform ABS INTERMITTENT CONDITION diagnostic procedure. 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 WSS speeds and compare graph while an assistant drives the vehicle.
  NOTE:
  If graph shows periodic dropouts pay close attention to the tone wheel.
3. 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) or not matching other wheels or showing erratic behavior?
  
  Yes
  - Go To 3
  No
  - Perform ABS INTERMITTENT CONDITION diagnostic procedure. Refer to ABS INTERMITTENT CONDITION .
CHECK FOR IMPROPER TIRE PRESSURE/MISMATCHED TIRES
1. Turn the ignition off. Remove the key from the Ignition Switch, close doors and allow the ABS Module to shut down.
  NOTE:
  Allow up to two minutes for the ABS Module to shut down. Opening the vehicle door will interrupt the shut down process.
2. Check and adjust the Left Front Tire pressure.
3. Check and adjust all other tire pressures.
4. Inspect for mismatched tires on vehicle.
  Is the tire improperly inflated or mismatched tires on vehicle?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
CHECK LEFT FRONT WHEEL BEARING FOR DAMAGE
1. Inspect the Left Front wheel bearing for excessive runout or clearance.
  NOTE:
  Refer to the appropriate service information, if necessary, for procedures or specifications.
  
  Is the Left Front Wheel Bearing Damaged?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 5
LEFT FRONT WHEEL SPEED SENSOR
1. Replace the Left Front Wheel Speed Sensor in accordance with the Service Information. Refer to SENSOR, WHEEL SPEED, FRONT, REMOVAL .
2. Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  CAUTION:
  Make sure brake capability is available before road testing.
3. Road test the vehicle over 40 km/h (25 mph).
  NOTE:
  Vehicle must be driven above 40 km/h (25 mph) for two minutes before set conditions are met.
4. With the scan tool, read the ABS DTCs.
  Does the DTC remain active?
  
  Yes
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Test Complete.