Temperature Sensor Voltage Below Normal
The ECM has detected a low voltage signal from the temperature sensor.
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What it means (plain English)
The temperature sensor is supposed to send a voltage signal to the engine control module (ECM) that reflects engine temperature, typically between 0.5V to 4.5V. If the voltage is below a certain level, usually around 0.1V, the ECM sees this as a problem, indicating the sensor might be faulty or there's a wiring issue.
What the computer is actually seeing
The ECM expects a voltage reading from the temperature sensor but receives a value significantly lower than the normal range, indicating a potential failure of the sensor or an open circuit.
What a healthy reading looks like
Normal voltage from the temperature sensor should be between 0.5V and 4.5V based on temperature; anything below 0.1V is considered faulty.
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. Inspect the wiring and connectors for the temperature sensor for any visible damage or corrosion.
- 22. Measure the voltage at the sensor connector with the key on and the engine off. Expected voltage should be between 0.5V and 4.5V.
- 33. If voltage is low, check the wiring continuity to the ECM. Use a multimeter to check for short circuits or breaks in the wire.
- 44. If wiring is good but voltage is still low, replace the temperature sensor and recheck the voltage.
- 55. If the new sensor shows correct voltage but the code returns, test the ECM for faults.
Common causes
- Faulty temperature sensor
- Damaged wiring or connectors
- Short circuit in the sensor circuit
- ECM issues
Typical repair cost
$$
Related codes
Frequently asked questions
Can I drive the vehicle with this fault?
It's driveable, but you may experience performance issues and should fix it soon.
Will this code come back after repair?
If the root cause (sensor/wiring) is addressed, the code should not return.
Why is this paired with other temperature sensor codes?
Multiple sensors may be monitored by the ECM, and failures can occur simultaneously.
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