Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
This DTC must be active for the results of this test to be valid.
1. Perform any Service Bulletins that may apply.
2. Turn the ignition on.
3. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
4. With the scan tool, read DTCs and record on the repair order.
5. With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.
6. With the scan tool, erase all DTCs.
  CAUTION:
  Make sure braking capability is available before road testing.
7. Road test the vehicle over 40 km/h (25 mph).
  NOTE:
  Vehicle must be driven above 40 km/h (25 mph) for set conditions to be met.
8. 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 FOR WHEEL SPEED SENSOR (WSS) RELATED DTCS
1. Refer to the recorded DTCs.
  Are there any WSS related DTCs active?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to ANTILOCK BRAKE SYSTEM (ABS) - DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK FOR IMPROPER TIRE PRESSURE/MISMATCHED TIRES
1. Turn the ignition off.
2. Check all the tire pressures.
3. Inspect for mismatched tires on vehicle.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
CHECK THE 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 one or more of the WSS speeds showing 0 km/h (0 mph) or not matching the other WSS speeds?
  
  Yes
  - Go To 5
  No
  - Perform ABS INTERMITTENT CONDITION diagnostic procedure. Refer to ABS INTERMITTENT CONDITION .
INSPECT WHEEL SPEED SENSOR (WSS) 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 6
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.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 7
REPLACE THE WHEEL SPEED SENSOR (WSS) AND TEST FOR DTCS
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 15 km/h (9 mph).
5. With the scan tool, read ABS DTCs.
  Does this DTC remain active?
  
  Yes
  - Go To 8
  No
  - Test complete.
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect the ABS Module harness connector.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Connect the ABS Module harness connector. Be certain that the harness connector is fully seated and the connector lock is fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect the related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase ABS DTCs.
  WARNING:
  To avoid possible serious or fatal injury, check brake capability is available before road testing.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read ABS Module 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 ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  - Test complete.