Transmission Fluid Temperature Sensor Circuit High
High voltage detected in the transmission fluid temperature sensor circuit.
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What it means (plain English)
The transmission fluid temperature sensor is sending a voltage reading that's too high, indicating a possible wiring issue, short circuit, or a bad sensor.
What the computer is actually seeing
The ECM sees voltage from the transmission fluid temperature sensor above the expected range, typically exceeding 5 volts. This high reading could show that the sensor is reporting extreme temperatures or there's a wiring problem.
What a healthy reading looks like
The normal voltage range for the transmission fluid temperature sensor should be 0.5 to 4.5 volts corresponding to temperatures of -40°F to 300°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.
- 1Check transmission fluid level and condition; fill or replace if needed. Decision: Is the fluid level low? Yes: Fill it and retest. No: Continue.
- 2Inspect the wiring harness and connectors for any visible damage or corrosion. Decision: Any issues found? Yes: Repair or replace wiring/connectors and retest. No: Continue.
- 3Use a scan tool to monitor the actual voltage reading from the transmission fluid temperature sensor. Decision: Is the voltage above 5 volts? Yes: Replace the transmission fluid temperature sensor. No: Continue.
Common causes
- Short circuit in the wiring harness
- Corroded connectors
- Faulty transmission fluid temperature sensor
- Failed ECM (rare)
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive the vehicle with this code?
Yes, but avoid heavy loads or rapid accelerations until fixed as it may lead to transmission overheating.
Will this code come back after clearing?
It might, especially if the underlying issue isn't fixed. Monitor voltages and wiring.
Why does this code appear with other transmission-related codes?
They often indicate related issues, such as temperature affecting shifting or performance.
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