What happens when temperature sensor fails to read?
If the measurement sequence fails due to noise or insufficient power, the subsequent measurement data will be +85°C (185°F) which is the power-on reset value of the temperature register. Be aware that a defective sensor can corrupt the measurement sequence and spoil the measurement for all of the sensors on the bus.
What should the temp of the coolant sensor be?
Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm. Get a wiring diagram and find out what ohms you should have at a specific temperature to check the function.
Can a reference temperature sensor be calibrated?
You can either generate an accurate temperature, or you can use a calibrated reference temperature sensor to measure the generated temperature. For example, you may insert the reference sensor and the sensor to be calibrated into a liquid bath (preferably a stirred one) and you can perform calibration at that temperature point.
What’s the reference voltage for a temperature sensor?
It has to be at least 10 µs for an accurate measurement (datasheet section about temperature sensor). Your next big flaw is in your thinking that the reference voltage is 1.21 V.
What should I do if my temperature sensor is not working?
Disconnect and reconnect the connections to the temperature sensor in question. Solder the connection wires if a faulty connection is suspected. Make sure there is plenty of metal to metal contact. Verify that the sensor is receiving +5V across the voltage source wire and the ground wire at the sensor connection.
How does the cylinder head temperature sensor work?
Some cars use a cylinder head temperature or CHT sensor instead of, or in addition to the ECT sensor. The CHT sensor (see the photo) works the same way, but it measures the temperature of the cylinder head metal and is not immersed in coolant. This allows the CHT sensor to measure the temperature of the engine correctly even with loss of coolant.
What is the correct temperature for a temperature sensor?
We have found that with the parasitic mode the sensor has insufficient energy to make temperature conversions and we DO NOT RECOMMEND this type of operation. The sensor response can be sporadic and will report the correct temperature, a temperature of 185°F (85°C), or no temperature at all (x.x).
How can I test the coolant temperature sensor?
Testing the ECT/CHT sensor Resistance: One way is to measure the resistance of the sensor at different engine temperatures and compare the readings to the specifications listed in the service manual. Measuring the resistance of the Engine coolant temperature (ECT) sensor.