Monitor Description

After the warm engine is stopped 

The ECM (included in the hybrid vehicle control ECU) monitors the intake air temperature variation in the period from when the engine was warmed up on the previous trip until the next engine start. If the change in engine coolant temperature sensor output is less than the threshold, it is determined that a malfunction has occurred in the intake air temperature sensor. When this is detected, the MIL is illuminated and the DTC is set.

After a cold engine is started 

The monitor runs when the engine is started cold after 5 hours or more have elapsed since the engine stopped. If the intake air temperature sensor output variation while the engine is warming up is less than the threshold, it is determined that a malfunction has occurred in the intake air temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is set.