Transmission Fluid Temperature
The Transmission Fluid Temperature is out of its normal 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 transmission temperature sensor is showing that the fluid is either too hot or too cold, which could hurt the transmission.
What the computer is actually seeing
The ECM reads the transmission fluid temp sensor data; normal temperatures should be between 70°C and 100°C.
What a healthy reading looks like
Transmission fluid temperature should be between 70°C (158°F) and 100°C (212°F) during normal operation.
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 the wiring and connectors to the transmission fluid temperature sensor for damage or corrosion. Result: Is wiring and connector secure? If No, repair or replace wiring/connector. If Yes, proceed to next step.
- 2Check transmission fluid level and condition. Result: Is fluid level low or does it look burnt? If Yes, top up with new fluid or replace fluid. If No, proceed to next step.
- 3Use a scan tool to live data stream the transmission fluid temperature. Result: Is the reading between 70°C and 100°C? If Yes, code may be an intermittent issue. If No, replace the transmission fluid temperature sensor.
Common causes
- Wiring issues to the sensor
- Faulty transmission fluid temperature sensor
- Low or contaminated transmission fluid
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive the vehicle with this code?
Yes, but it may affect shifting performance. Keep an eye on the transmission temperature.
Will this code come back after clearing it?
It can come back if the underlying issue isn't resolved.
Why does this code pair with SPN 774?
SPN 774 is related to transmission output sensor issues, both may arise due to similar underlying transmission problems.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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