Diagnostic Test

CHECK FOR DTC C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE
NOTE:
This DTC must be active for the results of this test to be valid.

NOTE:
If DTC C100A Left Front Wheel Speed Sensor Circuit is present it must be repaired before continuing.
1. Turn the ignition on.
2. With the scan tool, record and erase DTCs.
  CAUTION:
  Make sure braking capability is available before road testing.
3. Road test the vehicle over 25 mph (40 km/h).
  NOTE:
  Vehicle must be driven above 25 mph (40 km/h) for set conditions to be met.
4. With the scan tool, read DTCs.
  Does the scan tool display: C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE active?
  
  Yes
  - Go To 3
  No
  - Go To 2
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 25 mph (40 km/h).
  Is the Left Front WSS speed showing 0 mph (0 km/h) or not matching other wheels or showing erratic behavior?
  
  Yes
  - Go To 3
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to STANDARD PROCEDURE .
CHECK FOR IMPROPER LEFT FRONT TIRE PRESSURE/MISMATCHED TIRES
1. Turn the ignition off.
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 Left Front Tire improperly inflated or mismatched tires on vehicle?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK LEFT FRONT WSS LOOSENESS, INSPECT B8, B9 CIRCUITS/TERMINALS FOR DAMAGE
NOTE:
Check all terminals for broken, bent, pushed out, or corroded terminals
1. Inspect the Anti-Lock Brake Module harness connector, Left Front WSS, and Left Front WSS harness connector
2. Inspect the Left Front WSS for looseness, excessive corrosion and not properly fastened.
3. Inspect the (B8) Left Front WSS Signal and (B9) Left Front WSS Supply circuits between the Left Front WSS and Anti-Lock Brake Module for damage.
  Is the Left Front WSS loose or any of the wiring/connectors/terminals damaged?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 5
CHECK LEFT FRONT WHEEL SPEED SENSOR FOR DAMAGE
1. Remove the Left Front Wheel Speed Sensor
2. Inspect the Left Front Wheel Speed Sensor face for damage.
  Is the Left Front Wheel Speed Sensor damaged?
  
  Yes
  - Replace sensor and hub assembly.
  - Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 6
CHECK LEFT FRONT TONE WHEEL/BEARING FOR DAMAGE
1. Inspect the Left Front 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 Left Front Tone Wheel/Bearing damaged?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 7
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 STANDARD PROCEDURE .
  No
  - Go To 8
LEFT FRONT WHEEL SPEED SENSOR
1. Replace the Left Front Wheel Speed Sensor in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
3. Road test the vehicle over 25 mph (40 km/h).
  NOTE:
  Vehicle must be driven above 25 mph (40 km/h) for set conditions to be met.
4. With the scan tool, read ABS DTCs.
  Did DTC C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE reset?
  
  Yes
  - Replace the Anti-Lock Brake Module in accordance with the Service Information.
  - Perform ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete.