1 MAP sensor
2 Intake manifold flap vacuum unit
3 Intake manifold flap position sensor
Function
NOTE: In vehicles with a coated diesel particulate filter, a MAP sensor is installed on the intake manifold flap housing. The MAPT (Manifold Absolute Pressure And Temperature) sensor which may possibly be installed only fulfils the function of the IAT sensor.
During the active regeneration process the intake air is throttled. The MAP sensor measures the intake manifold pressure directly downstream of the throttle valve. The vacuum measured is used by the PCM for determining the mass air flow during the regeneration process.