Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
2023 Jeep Wagoneer L Base, RWDSECTION Diagnostic Test
WARNING: This page is about a different car, the 2023 Jeep Grand Wagoneer L and 2023 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR AN ACTIVE DTC
- Start the engine and allow it to idle.
- With the scan tool, read PCM DTCs.
Is this DTC active or pending?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK FOR HIGH RESISTANCE IN THE (D511) LIN BUS CIRCUIT
- Turn the ignition off.
- Disconnect the Alternator LIN BUS harness connector.
- Disconnect the PCM C2 harness connector.
- Measure the resistance of the (D511) LIN Bus circuit between the Alternator harness connector and PCM C2 harness connector.
Is the resistance below 2.0 Ohms?
Yes
- Go To 3
No
- Repair the (D511) LIN Bus circuit for a an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- REPLACE THE ALTERNATOR AND RETEST FOR DTC
- Replace the Alternator in accordance with the Service Information. Refer to GENERATOR, REMOVAL AND INSTALLATION .
- Reconnect the Alternator LIN BUS and PCM harness connectors.
- Turn the ignition on.
- With the scan tool, erase PCM DTCs.
- Using the Freeze Frame Data or When Monitored Conditions above, operate the vehicle within the conditions that set the DTC.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Go To 4
No
- Replacing the Alternator repaired the fault.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK RELATED HARNESS CONNECTIONS
- Disconnect all PCM 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.
- Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
- Connect all PCM 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.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to POWERTRAIN CONTROL MODULE .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- The wiring or poor connection problem has been repaired.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.