Here's why it's complicated:
* Sensor Type: Different vehicles use different types of ECT sensors (thermistors, thermistor-based, etc.). Each type has its own voltage-temperature characteristic curve. A higher voltage might indicate a higher temperature in one sensor design, but a lower temperature in another.
* Vehicle Make and Model: The acceptable voltage range is specified by the vehicle manufacturer. You need to consult your vehicle's service manual or a reliable online database specific to your car's year, make, and model.
* Operating Temperature: The voltage will vary significantly depending on the engine's operating temperature. A cold engine will produce a different voltage than a hot engine.
To determine if *your* ECT sensor voltage is acceptable:
1. Consult your vehicle's repair manual: This is the most reliable source of information. It will specify the correct voltage range for different temperatures.
2. Use a diagnostic scan tool: An OBD-II scanner can read the ECT sensor's voltage directly and often compare it to expected values. Many inexpensive scanners are available.
3. Use a multimeter: You can measure the voltage directly at the sensor connector, but you'll still need the vehicle's specifications to interpret the reading. Incorrectly connecting a multimeter can damage the sensor or vehicle electronics.
In short: Without knowing your specific vehicle, it's impossible to say whether a particular ECT sensor voltage is acceptable. Always refer to your vehicle's service manual or use a diagnostic tool for accurate assessment.
