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Coolant temp sensor calibration

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Hi, I’ve been struggling on how to correctly calibrate my coolant temp sensor. I’m using the mspnp2 on an red top sr20det with the stock coolant temp sensor but there isn’t any common sensor type in the drop down menu. How could I get this resolved so that I’m getting accurate ect readings?

As a temperature sensor is a non linear sensor, they are harder to calibrate as you cannot get two data points and extrapolate from there. What you can do is try and match the curve that the sensors has (most a re fairly similar) against another sensor calibration in the ECU. What you need to do is have the sensor exposed to three different temperatures whilst being connected to the ECU.

This is usually negative in the freezer, room temp and boiling water, you also need to have a known good temperature source to compare the reading from the sensor with that being generated in the ECU. You need to be able to log the voltages that the sensor outputs at each of these tested temperatures after soaking the sensor at the temperature for a number of minutes (some sensors can take up to 20 minutes to stabilse at a temperature).

When you have these voltage points, cross reference them with the other calibrations that are in the ECU and use the one with the closest fit.

Or just find a sensor that fits into the engine that the ECU also has a calibration for.