Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read ABS DTCs and record on the repair order.
3. With the scan tool, read and record the Environmental Data to help identify the conditions in which the DTC was set.
4. With the scan tool, erase the DTCs.
5. Start the engine.
6. Press and release the brake pedal.
7. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
CHECK THE (B15) BRAKE SIGNAL 1 FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Body Control Module (BCM) C4 harness connector.
3. Disconnect the Anti-lock Brake System (ABS) Module harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (B15) Brake Signal 1 circuit at the ABS Module harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (B15) Brake Signal circuit for a short to voltage.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (B15) BRAKE SIGNAL 1 FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Check for continuity between ground and the (B15) Brake Signal 1 circuit at the ABS Module harness connector.
  Is there continuity between ground and the ABS Module circuit?
  
  Yes
  - Repair the (B15) Brake Signal 1 circuit for a short to ground.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (B15) BRAKE SIGNAL FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (B15) Brake Signal 1 circuit between the BCM harness connector and the ABS Module harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Repair the (B15) Brake Signal 1 circuit for an open circuit or high resistance.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
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
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  - Test complete.