Diagnostic Test

WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
NOTE:
Diagnose any Communication DTCs before continuing.
1. Start the engine and allow it to idle.
2. With the scan tool, read DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE STOP/START MODE SWITCH OPERATION
1. Turn the ignition off.
2. Disconnect the Headlamp Switch harness connector.
  NOTE:
  The Stop/Start Mode Switch is combined with the Headlamp Switch.
3. Turn the ignition on.
4. With a scan tool, read PCM DTCs.
  NOTE:
  The DTC P05BF-00-STOP-START MODE SWITCH CIRCUIT HIGH should be active or pending with the Headlamp Switch harness connector unplugged.
  
  Does the scan tool display as described above?
  
  Yes
  - Replace the Headlamp Switch in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE STOP/START SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the BCM C8 harness connector.
3. Check for continuity between ground and the Stop/Start Switch Signal circuit at the Headlamp Switch harness connector.
  Is there continuity between ground and the Stop/Start Switch Signal circuit?
  
  Yes
  - Repair the Stop/Start Switch Signal circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK FOR THE STOP/START SWITCH SIGNAL CIRCUIT SHORTED TO THE SENSOR GROUND CIRCUIT
1. Check for continuity between the Stop/Start Switch Signal circuit and the Sensor Ground circuit in the Headlamp Switch harness connector.
  Is there continuity between the Stop/Start Switch Signal circuit and the Sensor Ground circuit?
  
  Yes
  - Repair the Stop/Start Switch Signal circuit for a short to the Sensor Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all BCM harness connectors.
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.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all 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.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the BCM in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .