Diagnostic Test
- CHECK FOR AN ACTIVE DTC NOTE:
This DTC must be active for the results of this test to be valid.
- Perform any Service Bulletins that may apply.
- Turn the ignition on.
- For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
- With the scan tool, read DTCs and record on the repair order.
- With the scan tool, erase all DTCs.WARNING:
To avoid personal injury or death, check brake capability is available before road testing.
- Road test the vehicle over 40 km/h (25 mph).NOTE:
Vehicle must be driven for several minutes above 40 km/h (25 mph) for set conditions to be met.
- With the scan tool, read BSCM DTCs.
Did the DTC return?
Yes
- Go To Next Step.
No
- Perform the BSCM-INTERMITTENT CONDITION TEST. Refer to BSCM INTERMITTENT CONDITION .
- CHECK CONNECTOR/TERMINAL FOR DAMAGE
- Turn the ignition off.
- Inspect the Wheel Speed Sensor for excessive debris on the sensor.NOTE:
Inspect connector installation and locks before disconnecting harness connectors.
- Disconnect the Wheel Speed Sensor harness and connector.
- Disconnect the BSCM harness connector.
- 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.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
No
- Go To Next Step.
- ISOLATE AND CHECK THE (B2) WHEEL SPEED SENSOR (+) CIRCUIT FOR A SHORT TO THE (B1) WHEEL SPEED SENSOR (-) CIRCUIT
- The ignition must be off when checking for a short between circuits.
- Isolate the circuit by disconnecting the BSCM harness connector and the WSS harness connector. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Connect the test leads of the DVOM and check for continuity between the circuits being tested at the component harness connector.NOTE:
There should be no continuity between the circuits being tested.
Is there continuity between the circuits?
Yes
- Repair the short between the circuits. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
No
- Go To Next Step.
- ISOLATE AND CHECK THE (B2) WHEEL SPEED SENSOR (+) CIRCUIT FOR A SHORT TO GROUND
- The ignition must be off when checking a circuit for continuity to ground.
- Isolate the circuit by disconnecting the BSCM harness connector and the WSS harness connector. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Connect the negative lead of the DVOM to a known good ground.
- With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.NOTE:
There should be no continuity between ground and the circuit being tested.
Is there continuity between ground and the circuit being tested?
Yes
- Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
No
- Go To Next Step.
- ISOLATE AND CHECK THE (B2) WHEEL SPEED SENSOR (+) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the BSCM harness connector and the WSS harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the WSS harness connector.
- Connect the other lead to the circuit being tested at the BSCM harness connector and measure the resistance of the circuit.
Is the resistance below 3.0 Ohms?
Yes
- Go To Next Step.
No
- Repair the circuit for an open/high resistance.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
- ISOLATE AND CHECK THE (B1) WHEEL SPEED SENSOR (-) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the BSCM harness connector and the WSS harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the WSSr harness connector.
- Connect the other lead to the circuit being tested at the BSCM harness connector and measure the resistance of the circuit.
Is the resistance below 3.0 Ohms?
Yes
- Go To Next Step.
No
- Repair the circuit for an open/high resistance.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
- CHECK THE (B2) WHEEL SPEED SENSOR (+) CIRCUIT FOR PROPER VOLTAGE AT THE WHEEL SPEED SENSOR (WSS) HARNESS CONNECTOR
- Turn the ignition off.
- Connect the BSCM harness connector.
- Disconnect the WSS harness connector.
- Turn the ignition on.
- Set the DVOM to measure DC voltage.
- Connect the negative lead of the DVOM to a known good ground.
- With the positive lead of the DVOM, measure the voltage of the circuit being tested at the WSS harness connector.NOTE:
Normal operating voltage should be above 9.0 volts.
Does the circuit have the proper voltage present?
Yes
- Go To Next Step.
No
- Go To 9
- REPLACE THE WHEEL SPEED SENSOR (WSS) AND TEST FOR DTCS
- Replace the Wheel Speed Sensor (WSS) in accordance with the Service Information. Refer to FRONT WHEEL SPEED SENSOR or REAR WHEEL SPEED SENSOR .
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
- Road test the vehicle over 40 km/h (25 mph).NOTE:
Vehicle must be driven for several minutes above 40 km/h (25 mph) for set conditions to be meet.
- With the scan tool, read BSCM DTCs.WARNING:
To avoid personal injury or death, check brake capability is available before road testing.
Does the DTC remain active?
Yes
- Go To Next Step.
No
- Test complete.
- CHECK RELATED HARNESS CONNECTIONS
- Turn the ignition off.
- Disconnect the BSCM harness connector.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Connect the BSCM harness connector. Be certain that the harness connector is fully seated and the connector lock is fully engaged.
- Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Connect the related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.WARNING:
To avoid possible serious or fatal injury, check brake capability is available before road testing.
- 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.
- With the scan tool, read BSCM DTCs.
Did the DTC return?
Yes
- Replace the Brake System Control Module (BSCM) in accordance with the Service Information. Refer to MODULE, BRAKE SYSTEM CONTROL (BSCM), REMOVAL AND INSTALLATION .
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
No
- The wiring or poor connection problem has been repaired.
- Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .