Transmission Control Module (TCM) Fault
Indicates a fault detected by the Transmission Control Module.
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 Transmission Control Module is like the brain that manages how the transmission shifts gears. If it sees something wrong, it triggers this code to alert you that it needs attention.
What the computer is actually seeing
The TCM monitors various parameters like input/output speeds, temperature, and gear positions. A fault can happen if it doesn’t see expected signals or if there is an internal failure.
What a healthy reading looks like
Input/output speeds should be between 0-3000 RPM; temperature readings typically around 180-220°F (82-104°C) when warm; expected voltage signals should be around 0.5-4.5 volts depending on the parameter being read.
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.
- 1Check for any visible wiring damage or corrosion in connectors related to the TCM.
- 2Inspect transmission fluid level and condition; should be within the specified range and not burnt or contaminated.
- 3Use a scan tool to clear the code and see if it returns. If it does, proceed.
- 4Check TCM power and ground pins; expect around 12-14 volts on the power pins.
- 5Monitor live data for input/output speed sensors while driving; verify they operate within expected ranges.
Common causes
- Bad TCM connection or wiring
- Faulty TCM
- Low transmission fluid
- Sensor issues like speed or temperature sensors
- Ground issues affecting the TCM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may be drivable, but shifting issues could arise. Better to fix sooner than later.
Will this code come back after clearing?
If the underlying issue isn't resolved, yes, it will likely return.
Why does this seem to pair with other codes?
Transmission and TCM faults often relate; issues in wiring or other sensors can trigger multiple codes.
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