Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Perform any Service Bulletins that may apply.
2. Turn the ignition on.
3. With the scan tool, read ABS DTCs and record on the repair order.
4. Cycle the ignition from off to on.
5. Press and hold the brake pedal.
6. Push the EPB Switch down to release the Electric Parking Brakes.
7. Push the EPB Switch up to set the Electric Parking Brakes.
8. Push the EPB Switch down to release the Electric Parking Brakes.
9. Release the brake pedal.
10. Cycle the ignition from off to on.
11. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - The conditions that caused this code to set are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAM/schematic as a guide, inspect the wiring harness and electrical connectors.
  - Perform the EPB VERIFICATION TEST. Refer to EPB VERIFICATION TEST .
CHECK CONNECTIONS ON THE HANDBRAKE ENGAGEMENT BUTTON AND ABS CONTROL UNIT
1. Check for loose, damaged or corroded connections on the hand brake engagement button or on the ABS control unit.
  Are there any loose or damaged connections?
  
  Yes
  - Repair the wiring connections as necessary.
  No
  - Go To 3
CHECK WIRING BETWEEN THE HANDBRAKE ENGAGEMENT BUTTON AND ABS CONTROL UNIT
1. Check the wiring for an open circuit or high resistance between the handbrake engagement button and PIN 38 of connector A of the ABS control unit.
  Is there a high resistance or open condition in the wiring?
  
  Yes
  - Repair the open circuit or high resistance in the wiring.
  No
  - Go To 4
CHECK WIRING BETWEEN THE HANDBRAKE ENGAGEMENT BUTTON AND ABS CONTROL UNIT
1. Check for wiring for a short circuit between the handbrake engagement button and PIN 38 of connector A of the ABS control unit.
  Is there a short circuit in the wiring?
  
  Yes
  - Repair the short circuit in the wiring.
  No
  - Go To 5
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 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 AND INSTALLATION .
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .