Transmission Fluid Temperature
Indicates the transmission fluid temperature is too high.
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What it means (plain English)
The transmission control module (TCM) is reading higher than normal temperatures in the transmission fluid, which can lead to premature wear or failure if not addressed.
What the computer is actually seeing
The TCM measures the transmission fluid temperature through a sensor near the transmission. It expects the temperature to be between 150°F and 200°F during normal operation. If the temperature exceeds these values, it triggers this fault code.
What a healthy reading looks like
Normal operating temperature range is typically 150°F to 200°F; anything above 220°F may trigger the code.
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 transmission fluid level; top off if low. Decision: Is fluid level okay? Yes: Go to step 2. No: Add fluid and retest. Code may clear.
- 22. Inspect connector and wiring to the transmission fluid temperature sensor for damage or corrosion. Decision: Is the wiring and connector okay? Yes: Go to step 3. No: Repair or replace as necessary and retest.
- 33. Confirm proper operation of the transmission fluid temperature sensor using a scan tool; compare actual temperatures to ECT readings. Decision: Is the sensor operating correctly? Yes: Go to step 4. No: Replace the sensor and retest.
- 44. Check if the vehicle is overheating; inspect coolant levels/temperature. Decision: Is the vehicle overheating? Yes: Address overheating first. No: Conclusion that fault might be an intermittent issue.
Common causes
- Failed transmission fluid temperature sensor
- Low transmission fluid level
- Contaminated or old transmission fluid
- Faulty wiring or connectors to the sensor
- Overheating due to towing or heavy loads
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's advisable to avoid prolonged driving as overheating can damage the transmission.
Will this problem come back?
If the underlying cause isn't fixed, it may return after clearing the code.
Why does this code pair with transmission performance issues?
High transmission fluid temperatures can affect shifting quality and lead to transmission failure.
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