Air Temperature Sensor ( Ambient / Intake ): Description and Operation

TMap Sensor
The TMAP (Temperature and Manifold Absolute Pressure) sensor contains a Manifold Absolute Pressure (MAP) Sensor and an Intake Air Temperature Sensor.


Manifold Absolute Pressure Sensor
The Manifold Absolute Pressure Sensor is a Piezo resistive pressure gauge that supplies an analog input to the EMS2000 corresponding to the absolute manifold pressure. The signal is used to determine the engine load. The engine load information is used for internal engine control via the EMS2000 and for ASC/DSC (traction control). This sensor has a maximum pressure range of 120 Kpa.

The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and rpm changes; and converts these into a voltage output. By monitoring the sensor output voltage, the EMS2000 knows the manifold pressure. At idle manifold pressure is lower (high vacuum) and output voltage will be about 1 to 2 volts. While at higher pressure or at Wide Open Throttle (lower vacuum) output voltage will be about 4 volts. The EMS2000 uses the MAP sensor to control fuel delivery and ignition timing.

Intake Air Temperature Sensor
The air intake temperature sensor is built into the TMap sensor. Air temperature information is used in conjunction with intake manifold pressure information as supplied by the MAP enabling the EMS2000 to calculate the volume of air being consumed by the engine. The sensor is a NTC type, supplied 5 volts by the EMS2000.

-High voltage readings at the EMS2000 indicate high sensor resistance, or low temperature.
-Low voltage readings indicate low sensor resistance or high temperature.