Transmission Fluid Temperature
Transmission fluid temperature is outside the normal range.
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What it means (plain English)
The transmission has a temperature sensor that checks how hot the fluid gets. If it gets too hot (over about 230°F for most systems), the computer knows something's wrong.
What the computer is actually seeing
The engine control unit (ECU) or transmission control unit (TCU) reads the transmission fluid temperature sensor voltage, which should be between 0.5 to 4.5 volts. A high reading (above 4.5V or below 0.5V) triggers this code.
What a healthy reading looks like
Normal transmission fluid temperature should be between 170°F to 220°F. Above 230°F is considered too hot.
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 the fluid level; it should be at the proper level as indicated on the dipstick.
- 2Inspect all wiring and connectors associated with the transmission fluid temperature sensor for damage or corrosion.
- 3Measure the voltage from the transmission fluid temperature sensor; it should be within 0.5 to 4.5 volts. If not, replace the sensor.
- 4Check the actual transmission fluid temperature using a scan tool; if it's within the expected range but the code persists, look for external factors like heavy load or towing.
Common causes
- Faulty transmission fluid temperature sensor
- Wiring issues or corroded connectors
- Contaminated transmission fluid
- Overheating transmission due to heavy loads or towing
- Insufficient fluid levels
Typical repair cost
$$ (200-600)
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe, but if the transmission is overheating, you should stop as it can cause severe damage.
Will this issue come back after resetting the code?
If the underlying problem isn't fixed, yes, the code will come back.
Why does this code pair with overheating issues?
An overheated transmission can trigger the fluid temperature sensor, causing this fault code.
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