Transmission Fluid Temperature Sensor 1 Voltage High
Transmission fluid temperature sensor is reporting a high voltage.
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What it means (plain English)
The transmission has a sensor that checks how hot the fluid is, and it's sending back a signal that's too high, which usually means there’s a problem with the sensor or its wiring.
What the computer is actually seeing
The transmission control module expects the transmission fluid temperature to be within a certain range, and if it sees a voltage above 4.9 volts, it triggers this fault code.
What a healthy reading looks like
Expected voltage from the sensor should range from 0.5V (cold) to 4.5V (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.
- 11. Check the freeze frame data to confirm when the fault occurred and the conditions.
- 22. Inspect the wiring and connectors to the transmission fluid temperature sensor. Look for frays, corrosion, or loose connections. Repair as necessary.
- 33. Using a multimeter, check the voltage at the sensor with the ignition on (engine off): you should see a reading between 0.5V to 4.5V. If it's higher than 4.9V, the sensor or wiring is likely bad.
- 44. If the wiring looks good, replace the transmission fluid temperature sensor. Clear the code and test drive the vehicle to see if it returns. Watch the temp readings while driving.
Common causes
- Faulty transmission fluid temperature sensor
- Wiring issues like shorts or breaks
- Poor connections in the sensor circuit
- Contaminated transmission fluid
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
It's generally safe to drive, but monitor transmission performance closely and get it fixed soon to avoid potential overheating damage.
Will this fault come back after I clear it?
If there is an underlying issue like a faulty sensor or wiring problem, the fault will likely return.
Why does this code pair with others?
It often pairs with sensor-related codes because multiple issues can exist in the same circuit or system.
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