Manifold Pressure/Vacuum Sensor: Testing and Inspection

Fig 49 MAP Sensor - Typical:

NOTE: To perform a complete test of MAP sensor (Fig. 49) and its circuitry, refer to Powertrain Management/Computers and Controls/Testing and Inspection/Diagnostic Charts. To test the MAP sensor only, refer to the following:

Fig 50 Rubber L-Shaped Fitting - MAP Sensor-to-Throttle Body:

1. Inspect the rubber L-shaped fitting from the MAP sensor to the throttle body (Fig. 50). Repair as necessary.

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

Fig 51 MAP Sensor Connector Terminals - Typical:

2. Test the MAP sensor output voltage at the MAP sensor connector between terminals A and B (Fig. 51). With the ignition switch ON and the 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 the same voltage described above to verify the wire harness condition. Repair as necessary
4. Test MAP sensor supply voltage at sensor connector between terminals A and C (Fig. 51) with the 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 the wire harness as necessary.
5. Test the MAP sensor ground circuit at sensor connector terminal A (Fig. 51) and PCM connector A-4.
- Repair the wire harness if necessary

Refer to Diagrams/Electrical/Connector Views for cavity locations.