Diagnostic Test
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
- With the scan tool, read DTCs in all Electronic Control Units (ECU's) and record on the repair order.
- With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read Body Control Module (BCM) DTCs.
Did the DTC return?
Yes
- Go To 2
No
- Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to: TESTING FOR AN INTERMITTENT CONDITION .
- DISCONNECT THE INTELLIGENT BATTERY SENSOR (IBS) HARNESS CONNECTOR - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
- Turn the ignition off.
- Disconnect the component harness connector(s) containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read BCM DTCs.
Did the DTC return?
Yes
- Go To 3
No
- Visually inspect the negative battery cable connection to the Intelligent Battery Sensor (IBS) for any damage or corrosion and repair as needed. If no problems are found, replace the Intelligent Battery Sensor (IBS) in accordance with the Service Information. Refer to: SENSOR, INTELLIGENT BATTERY (IBS), REMOVAL AND INSTALLATION .
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
- DISCONNECT THE UPPER SWITCH BANK MODULE HARNESS CONNECTOR - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
- Turn the ignition off.
- Disconnect the component harness connector(s) containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read BCM DTCs.
Did the DTC return?
Yes
- Go To 4
No
- Replace the Upper Switch Bank Module in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
- DISCONNECT THE UPPER SWITCH BANK 2 MODULE HARNESS CONNECTOR - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
- Turn the ignition off.
- Disconnect the component harness connector(s) containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read BCM DTCs.
Did the DTC return?
Yes
- Go To 5
No
- Replace the Upper Switch Bank 2 Module in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
- DISCONNECT THE BCM HARNESS CONNECTOR(S) AND CHECK THE (D401) LIN BUS 1 CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect all Electronic Control Unit (ECU) harness connectors for the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Turn the ignition on.
- Using a DVOM, measure the voltage on the circuit being tested at the component harness connector.NOTE:
When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
Is there any voltage present?
Yes
- Repair the circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
No
- Go To 6
- CHECK THE (D401) LIN BUS 1 CIRCUIT FOR A SHORT TO GROUND
- The ignition must be off when checking a circuit for continuity to ground.
- Connect the negative lead of the DVOM to a known good ground.
- Connect the positive lead of the DVOM to the circuit being tested at the ECU or component harness connector and check for continuity between the circuit and ground.NOTE:
When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
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 BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
No
- Go To 7
- DISCONNECT RELATED MODULE HARNESS CONNECTIONS AND INSPECT FOR PROBLEMS
- Disconnect all BCM harness connectors.
- 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 all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are 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 all 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.
- Using the recorded 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 BCM DTCs.
Did the DTC return?
Yes
- Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to: BODY CONTROL MODULE (BCM), REMOVAL AND INSTALLATION .
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
No
- Perform the BODY VERIFICATION TEST. Refer to: BODY VERIFICATION TEST .
- Test complete.