Part 2: Validation Of Time While Engine Is Off
A validation of the engine-off timer in the ECU is done between two driving cycles. The coolant temperature at engine off and at engine restart are evaluated. If the two temperatures indicate a short cool-down period, the engine-off timer is compared to a threshold value.
Specifically, if the engine is stopped with a coolant temperature above 75°C and is subsequently restarted at a temperature above 70 °C, then the engine-off timer is checked and an error is detected if the engine-off time is greater than 3 hours.