Transmission Fluid Temperature (TFT) Sensor Voltage Out of Range
Transmission fluid temperature sensor voltage is outside normal parameters.
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What it means (plain English)
The transmission fluid temperature sensor measures how hot the fluid is, and this code means the sensor is reporting a voltage reading that's too high or too low than expected.
What the computer is actually seeing
The engine control module (ECM) expects the TFT sensor to send a voltage between 0.5V to 4.5V, corresponding to fluid temperatures from about -40°F to 250°F.
What a healthy reading looks like
0.5V to 4.5V for temperatures -40°F to 250°F
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 wiring and connectors for damage and corrosion. Ensure tight connections.
- 22. Verify transmission fluid level; it must be within the proper range.
- 33. Using a scan tool, monitor the TFT sensor voltage; it should read between 0.5V and 4.5V.
- 44. If out of range, test the resistance of the TFT sensor; it should change with temperature. Replace if faulty.
- 55. If wiring and connectors are good and the sensor is within range, consider replacing the ECM.
Common causes
- Faulty temperature sensor
- Damaged wiring or connectors
- Low transmission fluid level
- Faulty ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means drivability might be affected; fix it soon.
Will the code come back after clearing?
It may return if the underlying issue isn't resolved.
Why does this code pair with SPN 1684?
SPN 1684 can indicate a problem with the vehicle speed sensor, which may also affect the TFT readings.
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