Okay, at this point, you may be wondering why you need to take the engine temperature to troubleshoot the sensor. Take the engine temperature at a location near the coolant temperature sensor.īefore going on to the next step, let's divert here for a second: Get the engine surface temperature using an infrared thermometer or a suitable cooking thermometer. Unplug the sensor electrical connector.Ģ.

Now that you've located the ECT sensor on your vehicle, you're ready to troubleshoot it.ġ. Complete the Coolant Temperature Sensor Test Photo courtesy of Andy / Andrew Fogg on Flickr. Use a digital multimeter to test your coolant temperature sensor.

Some sensors are buried under the intake plenum, especially on large trucks, and you need to remove the intake just to gain access to it.

Look for a large nut with an electrical connector on top and two electrical wires coming from the connector-on most modern vehicles-or one wire-on older vehicle models.

You can find the thermostat housing by following the upper radiator hose, which connects to the thermostat housing on the engine side. However, one of the most common locations is on or near the thermostat housing.

Depending on your particular vehicle model, you may find the sensor mounted on the cylinder head or intake manifold.

Open the hood of your vehicle to find the coolant sensor.

Wrench (ratchet and socket set, if you need to remove components).

On some vehicle models, a bad ECT sensor may upset the transmission, cooling fan, and temperature gauge as well.īut before you blame the coolant temperature sensor for your engine problems, use this guide to test the sensor to confirm that you actually need to replace it.On modern vehicles, a bad ECT sensor will upset ignition timing.Or it may cause a constant rich air/fuel mixture, causing an increase in emissions and fuel consumption.It may cause a constant lean air/fuel mixture, causing the engine to stall or idle roughly.A bad engine coolant temperature sensor affects engine performance:

Change coolant temperature sensor