Diagnosis of ambient air temperature: Notes

The diagnosis of the ambient air temperature sensor consists of a range check, a model based rationality check and a cold start rationality check of the temperature signal that the ECU receives via the CAN bus. The cold start rationality check is only performed after a cold start is detected and the model based rationality check is always executed if the monitoring conditions are fulfilled. Both tests mentioned above result in the same error path. The CAN signal itself is also checked by the CAN signal check.