![coolant temp sensor coolant temp sensor](http://www.autopartssupply.com.au/assets/full/CTS-013-Z12.jpg)
But this test will work great for a dead sensor. An intermittent fault will be difficult to catch using a voltmeter. A good scan tool has the ability to graph ECT performance and makes it easy to see interference or a signal dropping out momentarily. However, the results won’t be conclusive.
![coolant temp sensor coolant temp sensor](https://i.ebayimg.com/images/i/322400137372-0-1/s-l1000.jpg)
This test can be performed in or out of the vehicle. But for those that are interested, buckle up! Testing ECT resistance Bear in mind, sensors aren’t that expensive, and although I’m not in the habit of throwing parts at a car, I do understand, doesn’t make sense to buy test equipment to diagnose a $20 part. Here are basic tests you can perform to help diagnose a faulty ECT sensor.
#Coolant temp sensor code
These tools are a step above a simple code reader but still aren’t very expensive and will likely pay for themselves many times over. Testing a sensor, PCM, and its circuit will require a scan tool that reads live data. Can Bad Coolant Temperature Sensor Cause Car To Stall? Some systems use two ECT’s one for the PCM and a second for the radiator fan. A V engine may have an ECT for each bank. The third wire is usually employed to feed the dash temperature gauge.Īnd some higher-end models may employ more than one ECT. Some sensors may be a three-wire setup, don’t let this throw you off. As the coolant temperature rises, the resistance increases. A positive temperature coefficient is inverted. This type of sensor is however the more common type and is known as a negative temperature coefficient thermistor. It’s worth noting not all sensors work in this way. The higher the coolant temperature the less resistance the sensor offers and that translates into a higher return signal voltage to the PCM. It’s this reduced voltage the PCM uses to determine the coolant temperature. And since resistance is like a blockage in a garden hose pipe, not all the voltage returns. The second wire carries the reduced signal voltage back to the PCM.
![coolant temp sensor coolant temp sensor](https://www.autopartssupply.com.au/assets/full/CTS-009-12995.jpg)
One wire supplies the sensor with 5 volts. The two-wire electrical connector fitted to the sensor comes from the PCM. A typical sensor will, when cold read about 10,000 ohms and drop to about 200 when the engine is up to operating temperature. The sensor operates by changing resistance proportional to how hot its probe end is. The sensor simply threads into the engine with the probe end submerged in coolant inside the engine. The sensor comprises an electrical connector end and a probe end.