Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Coolant Temperature Sensor
The engine coolant temperature (ECT) sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.
< Reference data >Β
| Engine coolant temperature [Β°C (Β°F)] | Voltage(1) (V) | Resistance (kΞ©) | ||
|---|---|---|---|---|
| -10 (14) | 4.4 | 7.0 - 11.4 | ||
| 20 (68) | 3.5 | 2.35 - 2.73 | ||
| 50 (122) | 2.2 | 0.68 - 1.00 | ||
| 90 (194) | 0.9 | 0.236 - 0.260 | ||
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.