Transmission Control Module Power Input Signal Low
The power input signal to the transmission control module (TCM) is below acceptable limits.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The TCM isn't getting enough power, which can affect shifting and overall transmission performance.
What the computer is actually seeing
The TCM expects a nominal voltage around 12V from the power input. When it sees less than 10V for more than a few seconds, it triggers this code.
What a healthy reading looks like
Power input voltage should be between 11V to 14V when the vehicle is running.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the battery voltage. Should be at least 12.4V with the engine off and 13.7V to 14.7V with it running. If low, charge or replace the battery.
- 22. Inspect the TCM power circuit wiring and connectors for damage, corrosion, or loose connections. Repair as needed.
- 33. Check for any blown fuses related to the TCM. Replace any blown fuses and retest.
- 44. Use a multimeter to measure the voltage at the TCM power input connector. Should measure between 11V and 14V. If lower, trace the problem back through the circuit. If correct, suspect a faulty TCM.
Common causes
- Damaged wiring or connectors to the TCM
- Blown fuse in the TCM power circuit
- Faulty TCM
- Battery issues affecting voltage output
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best not to drive long distances as shifting can be erratic, risking transmission damage.
Will this code come back?
It may return if the underlying issue isn't fixed; address the root cause before clearing.
Why does this code appear with other transmission codes?
Multiple codes can indicate a systemic issue in the transmission system, often linked to power or communication issues.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →