Engine Temperature Sensor - Low Voltage
The engine temperature sensor is reporting a low voltage condition.
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What it means (plain English)
The engine temperature sensor connects to the engine computer and tells it how hot the engine is. If it sends a voltage under 0.1 volts, the computer thinks there’s a problem and triggers this code.
What the computer is actually seeing
The engine computer expects a signal voltage from the temperature sensor to be between 0.5 volts and 4.5 volts. A reading under 0.1 volts means it's recognizing a fault.
What a healthy reading looks like
Signal voltage should be between 0.5 to 4.5 volts when the engine is running.
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 to the wiring and connectors of the engine temperature sensor. Look for frays, corrosion or disconnections. If found, repair as necessary.
- 22. Inspect the coolant level in the engine. Make sure it's above minimum levels as low coolant can affect sensor readings.
- 33. Using a multimeter, measure the voltage at the engine temperature sensor connector. Expected should be 0.5-4.5 volts.
- 44. If voltage is below 0.1 volts, disconnect the sensor and test resistance. Replace if it's out of spec.
- 55. If sensor tests okay, check the wiring from the sensor to the engine control module (ECM) for continuity to eliminate wiring issues.
Common causes
- Faulty engine temperature sensor
- Wiring harness issues
- Corroded or damaged connectors
- Short in the circuit
- Poor ground connection
Typical repair cost
$$
Related codes
Frequently asked questions
Can I drive with this code?
Yes, but it's not recommended as it can affect engine performance and lead to overheating.
Will this code come back after I clear it?
It may come back if the underlying issue isn’t fixed, such as a bad sensor or wiring issue.
Why does this code pair with other codes?
It's common for related sensor codes to appear if multiple sensors share the same circuit or if there's a broader issue affecting the engine management system.
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