Transmission Fluid Temperature
The transmission fluid temperature is out of the expected range.
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 is telling you that the transmission fluid is either too hot or too cold, which can mess up how the transmission works.
What the computer is actually seeing
The engine control unit (ECU) monitors transmission fluid temperature through a temperature sensor. It expects the fluid to be between 160°F and 220°F (71°C - 104°C) during normal operation.
What a healthy reading looks like
Normal transmission fluid temperature should range from 160°F to 220°F (71°C - 104°C).
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; top off if low. Decision: If low, fill and retest.
- 22. Inspect wiring and connectors at the transmission fluid temperature sensor for damage or corrosion. Decision: If damaged, repair or replace.
- 33. Use a scan tool to monitor live data from the transmission fluid temperature sensor. Decision: If readings are erratic or outside normal range, replace the sensor.
- 44. Check resistance values of the sensor at various temperature points. Decision: If resistance is not within spec (typically 2.5 ohms at 200°F), replace the sensor.
Common causes
- Faulty transmission fluid temperature sensor
- Wiring issues or bad connections at the sensor
- Low transmission fluid level
- Faulty transmission control module (TCM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means it's best to fix soon, but the vehicle should still be drivable unless experiencing transmission issues.
Will this code come back after clearing it?
If the underlying issue isn't fixed, yes, the code will likely return.
Why do I see this code with SPN 552?
SPN 552 is often related as it's also about transmission temperatures, indicating potential overheating or sensor issues.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →