Manifold Pressure/Vacuum Sensor: Testing and Inspection

Sensor Location(4.0L Engine):

To perform a complete test of MAP sensor and its circuitry, refer to DRB scan tool and appropriate Powertrain Diagnostics Procedures. To test the MAP sensor only, refer to the following:

Rubber L-Shaped Fitting-MAP Sensor-to-Throttle Body:

1. Inspect rubber L-shaped fitting from MAP sensor to throttle body. Repair as necessary.

CAUTION: When testing the MAP sensor, be sure that the harness wires are not damaged by the test meter probes.

MAP Sensor Connector Terminals-Typical:

2. Test MAP sensor output voltage at MAP sensor connector between terminals A and B. With ignition switch ON and engine OFF, output voltage should be 4-to-5 volts. The voltage should drop to 1.5-to-2.1 volts with a hot, neutral idle speed condition.
3. Test Powertrain Control Module (PCM) cavity A-27 for same voltage described above to verify wire harness condition. Repair as necessary.
4. Test MAP sensor supply voltage at sensor connector between terminals A and C with ignition ON. The voltage should be approximately 5 volts (±0.5V). Five volts (±0.5V) should also be at cavity A-17 of the PCM wire harness connector. Repair or replace wire harness as necessary.
5. Test the MAP sensor ground circuit at sensor connector terminal-A and PCM connector A-4. Repair wire harness if necessary.