Manifold Absolute Pressure (MAP) Sensor-PCM Input

Fig. 7 Intake Air Temp. Sensor Location-Typical:

OPERATION
The MAP sensor reacts to absolute pressure in the intake manifold. It provides an input voltage to the Powertrain Control Module (PCM). As engine load changes, manifold pressure varies. The change in manifold pressure causes MAP sensor voltage to change. The change in MAP sensor voltage results in a different input voltage to the PCM. The input voltage level supplies the PCM with information about ambient barometric pressure during engine start-up (cranking) and engine load while the engine is running. The PCM uses this input along with inputs from other sensors to adjust air-fuel mixture.

The MAP sensor is mounted on the side of the engine throttle body (Fig. 7). The sensor is connected to the throttle body with a rubber L-shaped fitting.

CIRCUIT OPERATION
From the Powertrain Control Module (PCM), circuit K7 supplies 5 Volts to the manifold absolute pressure (MAP) sensor Circuit K7 connects to cavity A17 of the PCM.

Circuit K1 delivers the MAP signal to the PCM. Circuit K1 connects to cavity A27 of the PCM.

The PCM provides a ground for the MAP sensor signal (circuit K1) through circuit K167. Circuit K167 connects to cavity A4 of the PCM.