Grand Prix V6-204 3.4L DOHC (1992)
Manifold Pressure/Vacuum Sensor: Testing and Inspection
Manifold Absolute Pressure (MAP) Sensor Circuit Diagram
CIRCUIT DESCRIPTION
The Manifold Absolute Pressure (MAP) sensor measures the ablolute pressure inside the intake manifold, which changes depending on throttle
position, engine speed and engine load. The PCM applies a 5 volt reference voltage to a terminal of the MAP sensor. Depending on the absolute
pressure in the intake manifold, the MAP sensor divides the current from the reference source between a signal circuit and ground at different ratios,
which varies the voltage in the signal circuit. Each specific signal voltage corresponds to a specific absolute pressure. The lower the manifold pressure
(high vacuum), the lower the voltage output from the MAP sensor. The sensors output ranges from about 1-2 volts at idle, to about 4-4.8 volts at wide
open throttle. The PCM monitors the MAP sensor signal voltage and calculates the pressure in the intake manifold.
TEST DESCRIPTION