Flow of Diagnosis

Diagnosis of Ambient Air Temperature and Signal via CAN

This diagnosis compares the measured ambient air temperature to the modeled ambient air temperature, if the enable conditions are set.

The enable conditions are:
- Intake air temperature signal useful
- integrated air mass flow since engine start above threshold
- air mass, engine speed and vehicle speed above threshold constantly
- ambient air temperature via CAN useful

The ambient air temperature signal and the faults are taken from CAN. A broken CAN dependent to a fault "ambient air temperature via CAN"

CAN timeouts or the un useful CAN signal "Tamb." causes a signal fault.

Flow chart Diagnose of Ambient Air Temperature Sensor (plaus check)







Flow chart Diagnose of Ambient Air Temperature Sensor (sig check)







Flow chart Diagnose of Ambient Air Temperature Sensor (range fault)