Redundant Engine Temperature Sensor Failure
The engine temperature sensor has failed, causing inaccurate temperature readings.
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)
Your engine has multiple temperature sensors, and one of them is sending a bad signal to the computer. This can cause the engine to run too rich or too lean, potentially leading to overheating.
What the computer is actually seeing
The Engine Control Module (ECM) is receiving signals that the engine temperature is outside of the normal range, specifically if the temperature is reported at 0°C (32°F) or exceeds predetermined thresholds based on the failed sensor.
What a healthy reading looks like
Normal engine operating temperature should be between 80°C (176°F) and 95°C (203°F). Volts from the sensor should be around 0.5V (cold) to 4.5V (hot).
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 for visible damage or corrosion on the wiring and connectors going to the engine temperature sensor.
- 22. Measure the resistance of the temperature sensor; it should vary inversely with temperature (approximately 3000 ohms at 0°C). If it’s out of spec, replace the sensor.
- 33. Inspect and test the ECM for error codes specific to the engine temp sensors to confirm if the issue resides with the sensor or the ECM itself.
Common causes
- Wiring short or open circuit to the temperature sensor
- Faulty temperature sensor
- Faulty ECM
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's not safe; engine overheating could occur, and it affects performance.
Will this code come back after clearing it?
Yes, if the underlying issue isn't fixed, the code will return.
Why does it pair with SPN 4371 and SPN 4372?
These codes commonly indicate issues related to the redundant sensor setup and can all have ties to incorrect engine 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 →