Transmission Oil Temperature Sensor
Transmission oil temperature sensor circuit problem.
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 transmission oil temperature sensor is not giving the right temperature readings, which can mess with how the transmission works and even damage it if not fixed.
What the computer is actually seeing
The computer sees a voltage signal that is outside the expected range from the transmission oil temperature sensor, indicating a possible fault in the sensor or circuit.
What a healthy reading looks like
Expected voltage from the sensor should be between 0.5V (cold, ~0°C) and 4.5V (hot, ~100°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 and condition; top off or replace as necessary.
- 22. Inspect the wiring and connectors at the transmission oil temperature sensor for damage or corrosion; repair any issues found.
- 33. Test the voltage at the sensor connector; it should be between 0.5V and 4.5V when the engine is running.
- 44. If voltage is out of range, replace the transmission oil temperature sensor.
- 55. If the sensor is good and wiring is intact, check the Engine Control Module (ECM) for faults. Confirm no other related codes are present.
Common causes
- Damaged wiring or connectors to the sensor.
- Faulty transmission oil temperature sensor.
- Low transmission fluid level or improper fluid type.
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderately safe for short distances but can cause transmission overheating if ignored.
Will this problem come back after a reset?
It can come back if the underlying issue (like a bad sensor or wiring problem) isn't fixed.
Why do I see this code along with SPN 1203?
SPN 1203 often indicates poor transmission performance related to the temperature readings.
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 →