Transmission Fluid Temperature Sensor 1 - Voltage Above Normal
Transmission fluid temperature sensor is reading too high.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer monitors the transmission fluid temperature via a sensor. If it detects a voltage that indicates the fluid is hotter than normal, it triggers this code.
What the computer is actually seeing
The control module is reading a voltage signal from the transmission fluid temperature sensor that exceeds the typical range, generally above 5 volts.
What a healthy reading looks like
Transmission fluid temperature should be between 70°F and 210°F (21°C to 99°C) under normal operating conditions, with corresponding voltages generally between 0.5V to 4.5V.
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 wiring and connectors to the transmission fluid temperature sensor for damage or corrosion. Fix any issues found and retest. Decision point: Did the code persist? Yes: Go to step 2. No: Problem fixed.
- 22. Check the transmission fluid level; ensure it's within the proper range. If low, top it off and monitor for the code. Decision point: Did the code return? Yes: Go to step 3. No: Problem likely resolved.
- 33. Measure the voltage at the transmission fluid temperature sensor while the vehicle is running. It should be between 0.5V to 4.5V. Decision point: Is the voltage within the expected range? Yes: Go to step 4. No: Replace the sensor and retest.
Common causes
- Faulty transmission fluid temperature sensor
- Wiring issues (shorts, corrosion)
- Faulty transmission control module (TCM)
- Overheating transmission due to low fluid or heavy towing
- Calibration issues after a transmission repair
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive but may cause shifting issues or overheating. Monitor closely.
Will the code come back after clearing it?
If the underlying issue isn't resolved, yes, the code will likely return.
Why does this code sometimes pair with overheating warnings?
Because both indications relate to the transmission fluid temperature, excessive heat can cause both issues.
Working a real vehicle right now?
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