Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read and record the DTCs on the vehicle 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 ABS DTCs.
5. Start the engine.
6. Slowly press the brake pedal and release.
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 .
INSPECT THE BRAKE PEDAL POSITION (BPP) SENSOR FOR INCORRECT INSTALLATION, DAMAGE OR MECHANICAL FAILURE
1. Turn the ignition off.
2. Visually inspect the BPP Sensor for Improper installation, damage or mechanical failure. Refer to SENSOR, STOP LAMP, REMOVAL AND INSTALLATION .
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 3
(B137) BPP SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
1. Disconnect the ABS Module harness connector.
2. Disconnect the BPP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (B137) BPP Sensor Signal circuit in the BPP Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (B137) BPP Sensor Signal circuit for a short to voltage.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
(B937) BPP SENSOR RETURN CIRCUIT SHORTED TO VOLTAGE
1. Measure the voltage of the (B937) BPP Sensor Return circuit in the BPP Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (B937) BPP Sensor Return circuit for a short to voltage.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 5
(B237) BPP SENSOR FEED CIRCUIT SHORTED TO THE (B137) BPP SENSOR SIGNAL CIRCUIT
1. Turn the ignition off.
2. Measure the resistance between the (B237) BPP Sensor Feed circuit and the (B137) BPP Sensor Signal circuit in the BPP Sensor harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the (B237) BPP Sensor Feed circuit and the (B137) BPP Sensor Signal circuit for a short.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 6
BRAKE PEDAL POSITION (BPP) SENSOR
1. Connect the ABS Module harness connector.
2. Turn the ignition on.
3. Measure the voltage at the BPP Sensor harness connector between the (B237) BPP Sensor Feed and the (B937) BPP Sensor Return.
  Is the voltage above 4.75 volts?
  
  Yes
  - Replace the Brake Pedal Position (BPP) Sensor in accordance with the Service Information. Refer to SENSOR, STOP LAMP, REMOVAL AND INSTALLATION .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 7
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.