1 IAT sensor
2 Intake manifold flap servo motor
3 Intercooler bypass flap servo motor
During regeneration of the diesel particulate filter, a constant intake air temperature in conjunction with the intercooler bypass and the intake manifold flap is of great importance.
For this reason, an additional IAT sensor is installed in the airflow, downstream of the intercooler bypass. This is used to set the most favorable air intake temperature during the regeneration phase.
When the engine is operating normally, the IAT sensor has no function.
Effects of faults
In the event of a fault, the PCM performs the calculations using a substitute value.
Diagnosis
The IAT sensor is checked by the monitoring system for short (to ground and positive) and open circuits.
As the PCM is able to use a substitute value to perform its calculation when the signal fails, the impact of this failure on the regeneration phase of the particulate filter is only minimal. The EOBD limits are not affected by this. Therefore, this is a non MIL active component.
Possible diagnostic trouble codes: P0097, P0098.