Transmission Fluid Temperature Too High
The transmission fluid is overheating.
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What it means (plain English)
The computer is detecting that the transmission fluid temperature is higher than normal, usually above 200°F (93°C), which can cause serious damage to the transmission if not addressed immediately.
What the computer is actually seeing
The ECM receives a high signal from the transmission temperature sensor (typically a thermistor) indicating temperatures above the set threshold, often over 200°F (93°C).
What a healthy reading looks like
Transmission fluid should normally operate between 175°F to 200°F (79°C to 93°C).
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. Inspect the transmission fluid level and condition. Look for signs of leakage or contamination. Decision: If low, top off and retest; if okay, move to step 2.
- 22. Check the transmission temperature sensor wiring and connector for damage or corrosion. Decision: Repair if necessary; if wiring is intact, proceed to step 3.
- 33. Using a scan tool, monitor the transmission fluid temperature while running the engine. Compare with expected values. Decision: If temperature readings are normal, the sensor may be faulty; if high, proceed to step 4.
- 44. Inspect the transmission cooler for obstructions or leaks. Ensure it's functioning correctly and the coolant routes are clear. Decision: Repair as needed; if cooler is good, consider replacing the transmission temperature sensor.
Common causes
- Low transmission fluid level
- Faulty transmission temperature sensor
- Cooling system failure
- Clogged transmission cooler
- Severe driving conditions
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
No, driving with overheating transmission fluid can cause severe damage to the transmission.
Will this code clear on its own after repairs?
Yes, once the issue is resolved and the ECU sees normal temperatures, the code should clear automatically after a drive cycle.
Why does this code appear with other transmission-related codes?
High transmission fluid temperature can be a common side effect of other transmission issues, which can also trigger additional fault codes.
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