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, erase all DTCs.
6. Turn the ignition off for a minimum of 10.0 seconds.
7. Press the brake pedal firmly and hold.
8. Pull the EPB Switch up to set the Electric Parking Brakes.
9. Release the brake pedal.
10. Press the brake pedal firmly and hold.
11. Push the EPB Switch down to release the Electric Parking Brakes.
12. Release the brake pedal.
13. Turn the ignition on.
14. 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 wiring diagram/schematic as a guide, inspect the wiring harness and electrical connectors.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
(A838) SWITCHED B+ CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the EPB Switch harness connector.
3. Disconnect the Body Control Module (BCM) C7 harness connector.
4. Measure the resistance of the (A838) Switched B+ circuit between the EPB Switch harness connector and the BCM C7 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (A838) Switched B+ circuit for an open or high resistance.
  - Perform the EPB VERIFICATION TEST. Refer to EPB VERIFICATION TEST .
(A838) SWITCHED B+ CIRCUIT SHORT TO GROUND
1. Check for continuity between ground and the (A838) Switched B+ circuit at the EPB Switch harness connector.
  Is there continuity between ground and the (A838) Switched B+ circuit?
  
  Yes
  - Repair the (A838) Switched B+ circuit for a short to Ground
  - Perform the EPB VERIFICATION TEST. Refer to EPB VERIFICATION TEST .
  No
  - Go To 4
(Z930) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Z930) Ground circuit between the EPB Switch harness connector and the EPB Module harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (Z930) Ground circuit for an open or high resistance.
  - Perform the EPB VERIFICATION TEST. Refer to EPB VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect the ABS Module harness connector.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Connect the ABS Module harness connector. Be certain that the harness connector is fully seated and the connector lock is fully engaged.
7. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Connect the related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
  WARNING:
  To avoid personal injury or death, check brake capability is available before road testing.
10. 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.
11. 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
  - The wiring or poor connection problem has been repaired.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .