The B/MAP sensor used on 3.8L engines is separate from the barometric sensor and is located on the left fender panel in the engine compartment. The barometric sensor signals the PCM of changes in atmospheric pressure and density to regulate calculated air flow into the engine. The MAP sensor monitors and signals the PCM of changes in intake manifold pressure which result from engine load, speed and atmospheric pressure changes.
The Manifold Absolute Pressure (MAP) sensor measures the pressure in the intake manifold and sends a variable frequency signal to the Powertrain Control Module (PCM). When the ignition is ON and the engine OFF , the MAP sensor will indicate the barometric pressure in the intake manifold.
See Figures 1, 2 and 3
- Connect MAP/BARO tester to sensor connector and sensor harness connector. With ignition ON and engine OFF , use DVOM to measure voltage across tester terminals. If the tester's 4-6 volts indicator is ON, the reference voltage input to the sensor is okay.
- If the DVOM voltage reading is as indicated in the table, the sensor is okay.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Disconnect the electrical wiring and the vacuum line from the sensor.
- Remove the sensor mounting bolts and remove the sensor.
- Install the sensor with the mounting bolts and tighten.
- Attach the electrical wiring lead to the sensor.
- Attach the vacuum line to the sensor.
- Connect the negative battery cable.