Transmission Fluid Temperature High
Transmission fluid temperature is too high.
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What it means (plain English)
The computer is reading that the transmission fluid is over its normal operating temperature, which should typically be between 160°F and 220°F. If it gets too hot, it can lead to transmission damage.
What the computer is actually seeing
The transmission control module (TCM) sees a signal from the temperature sensor indicating a fluid temperature higher than 220°F.
What a healthy reading looks like
Normal fluid temperature readings should range from 160°F to 220°F; anything above this is considered too high.
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 transmission fluid level. It should be between the 'Full' and 'Add' marks when checked with the engine running and warm. If low, add the correct fluid type and check for leaks.
- 22. Inspect the wiring and connector to the transmission fluid temperature sensor for damage or corrosion.
- 33. Test the transmission fluid temperature sensor for proper operation. At room temperature, it should read around 70°F. When heated, it should accurately reflect increases in fluid temperature. Consult your service manual for the exact resistance values at different temperatures.
- 44. If fluid levels and wiring are good but the code persists, perform a temperature test of the transmission fluid using a scan tool to confirm the TCM reading against an external gauge.
Common causes
- Low transmission fluid level
- Faulty transmission fluid temperature sensor
- Blocked transmission cooler
- Sludge build-up in the transmission
- Overheating due to heavy towing or loaded conditions
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's advisable to drive calmly and avoid heavy towing or load until the issue is resolved, as prolonged high temperatures can damage the transmission.
Will the problem come back after repair?
If the underlying cause, such as low fluid or a bad sensor, is fixed, it should not return.
Why does this code sometimes appear together with overheating issues?
Excess transmission fluid temperature can indicate overheating due to heavy loads, poor fluid circulation, or insufficient cooling.
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