Trooper LS 2WD V6-3.5L (2001)
Manifold Absolute Pressure Sensor: Testing and Inspection
Manifold Absolute Pressure (MAP) Output Check
Circuit Description
The manifold absolute pressure (MAP) sensor measures the changes in the intake MAP which result from engine load (intake manifold vacuum) and
engine speed changes; and converts these into a voltage output. The powertrain control module (PCM) sends a 5-volt reference voltage to the MAP
sensor. As the MAP changes, the output voltage of the sensor also changes. By monitoring the the sensor output voltage, the PCM knows the MAP. A
lower pressure (low voltage) output voltage will be about 1-2 volts at idle. Higher pressure (high voltage) output voltage will be about 4-4.8 volts at
wide open throttle. The MAP sensor is also used, under certain conditions, to measure barometric pressure, allowing the PCM to make adjustments for
different altitudes. The PCM uses the MAP sensor to diagnose proper operation of the EGR system, in addition to other functions.