Monitor Description

Engine Coolant Temperature Sensor Cold Start Monitor 

The monitor runs when the engine is started cold. If the change in engine coolant temperature sensor output until the engine is warmed up completely is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.

Engine Coolant Temperature Sensor Soak Monitor 

When more than 5 hours have elapsed since the engine was stopped, the ECM compares the engine coolant temperature from the time the warmed-up engine is stopped with the engine coolant temperature when the engine is started on the next trip. If the change in engine coolant temperature sensor output is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.