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
- VERIFY THE DTC IS ACTIVE NOTE:
For vehicle communication problems, use the scan tool to refer to the network review screen. This screen depicts a high level view of the vehicle network. Fault and problem areas appear in red. Selecting any of the network components allows access to the source of the problem.
- Ignition on, engine not running.
- With a scan tool, read DTCs.
Is the DTC active at this time?
Yes
- Perform diagnostic procedure U0101-LOST COMMUNICATION WITH TCM for 3.6L or U0101-LOST COMMUNICATION WITH TCM for 5.7L.
No
- Refer to Diagnosis and Testing and perform the Stored Lost Communication DTCs diagnostic procedure.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.