Intake-air temperature/intake pressure sensor (TMAP)
The TMAP sensor contains a sensor for the intake-air temperature and the intake pressure.
This sensor is used in conjunction with the MAP sensor to determine the intake air volume. The engine control unit uses this signal to calculate the fuel/air ratio.
This sensor is a piezo element that provides the engine control unit with an analog input signal related to the intake air pressure. The signal is used to determine the engine load. The engine load information is used for the internal engine control. In cars with automatic gearboxes, this signal is used for torque reduction during gearshifts.
The R50 requires only one TMAP sensor with a maximum pressure of 120 kPa. On the R53, the pressure differential to the compressor is measured to determine the intake air compression. To achieve this, 2 sensors are fitted - one before and one after the compressor. The TMAP sensor is fitted on the manifold side and it has the same technical data as the base sensor, but with a maximum pressure of 250 kPa. The other sensor is fitted before the TMAP sensor between the compressor and the throttle-valve housing and it measures the air pressure. It corresponds to the base TMAP sensor, with the difference that no temperature sensor is integrated.
On the R50 and R53, the TMAP sensor is located on the intake pipe of the 1st cylinder.
On the R53, the MAP sensor (MAP_UP) is located between the throttle-valve housing and the compressor.
Intake-air temperature sensor
In the event an intake air temperature sensor failure, a fault code is entered in the engine control unit. The car will have problems with cold starts, poor running characteristics, increased emissions and power loss at higher outdoor temperatures.
Intake manifold absolute pressure sensor
In the event of a MAP sensor failure, a fault code is entered in the engine control unit and a substitute value is used. The car then has starting problems, unstable idling and misfires. The MIL is activated.