Oil Temperature Sensor For ECM: Description and Operation

Engine Oil Temperature Sensor

High/Low Input Failure
These are continuous monitors. The voltage from the sensor is compared to a failure threshold defined in the software. If the voltage is below the low threshold, then a timer starts to increment. Once this timer exceeds another threshold, then a failure flag is set and a DTC is stored. If the voltage is over the high threshold defined in the software, then a timer starts to increment. Once this timer exceeds a threshold, then a failure flag is set and a DTC is stored.

Range/Performance Failure
The EOT movement is monitored during the warm up phase of a trip. If the ECT is cool enough at start and rises by the required amount then a judgment is made on the EOT. If the EOT movement (maximum reading for the trip - minimum reading for the trip) has not been sufficient then a failure judgment will be made.