Engine Coolant Temperature Sensor Fault
The engine coolant temperature sensor is malfunctioning.
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 engine keeps track of how hot the coolant is to adjust fuel and air mix. If the sensor fails, it can provide incorrect readings about the engine’s temperature, affecting performance.
What the computer is actually seeing
The ECM expects a voltage signal from the engine coolant temperature sensor that varies between 0.5V (cold) and 4.5V (hot). If it sees a constant voltage or an out-of-range value, it triggers the fault code.
What a healthy reading looks like
Cold: 0.5V (approx. 0°C), Hot: 4.5V (approx. 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 engine coolant level; ensure it’s within the acceptable range before proceeding.
- 22. Inspect the wiring and connectors at the engine coolant temperature sensor for any visible damage or corrosion.
- 33. Measure the voltage at the coolant temperature sensor connector; it should range from 0.5V at cold start to approximately 4.5V at operating temperature.
- 44. If voltage readings are out of range, replace the coolant temperature sensor; if readings are within range, check the wiring continuity from the sensor to the ECM.
Common causes
- Faulty engine coolant temperature sensor
- Wiring harness issue (shorts or breaks)
- Corroded connectors at the sensor or ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means you can drive it, but the engine may run poorly and consume more fuel. Fix it soon.
Will this code come back after clearing it?
If the underlying issue isn't resolved, yes, the code will likely return after clearing.
Why does this code pair with others?
It's common for multiple codes to register from the same system; other sensors may be impacted due to the faulty temperature readings.
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