Transmission Fluid Temperature Sensor 1
Transmission fluid temperature sensor is reading out of range.
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What it means (plain English)
The transmission fluid temperature sensor measures how hot the transmission fluid is. If the fluid gets too hot, it can damage the transmission. This code means the sensor is either sending a signal that's too high or too low.
What the computer is actually seeing
The computer looks for the temperature signal from the sensor, which should typically range from 70°F to 250°F (21°C to 121°C) while operating. Out of this range triggers the fault.
What a healthy reading looks like
Normal operation temperature is 170°F to 230°F (77°C to 110°C) under normal load conditions; above 250°F triggers a fault.
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. Ensure it's at the correct level on the dipstick. If low, top off and see if the code returns after driving.
- 22. Inspect the wiring and connector at the transmission fluid temperature sensor for signs of damage or corrosion. Repair any issues found.
- 33. Use a scan tool to monitor the transmission fluid temperature sensor's live data. Check if the readings are within expected values (70°F to 250°F).
- 44. If readings are erratic or out of range, disconnect the sensor and measure the resistance (should be 2-5 ohms at room temp). If out of spec, replace the sensor.
- 55. Clear the code and test drive the vehicle to see if the code returns.
Common causes
- Faulty transmission fluid temperature sensor
- Wiring issues in the sensor circuit
- Transmission fluid contamination or low level
- Poor electrical connection at the sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can drive but should fix it soon to avoid transmission damage.
Will this code come back after fixing?
If the sensor or wiring is repaired correctly and the fluid is at the right level, it shouldn't return.
Why do I also see SPN 1580 with this code?
SPN 1580 relates to transmission oil pressure; both codes often trigger together due to related sensor issues.
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