Manifold Pressure/Vacuum Sensor Location for 1994 Dodge Ram 3500 Pickup
Manifold Pressure/Vacuum Sensor: Testing and Inspection
NOTE:
To perform a complete test of Manifold Absolute Pressure (MAP) sensor and its circuitry, refer to appropriate Powertrain Diagnostic Chart. To
test the MAP sensor only, refer to the following:
PROCEDURE
Throttle Body
1.
Inspect the rubber nipple (fitting) from the MAP sensor to the 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 the MAP sensor output voltage at the MAP sensor connector between terminal A and terminal B.
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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) (terminal/pin-1) 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 terminal A and terminal C with the ignition ON.
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The voltage should be approximately 5 volts (±O.5V). Five volts (±0.5V) should also be at terminal 6 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 and PCM connector terminal/pin-4. Repair the wire harness if necessary.
6.
Test the MAP sensor ground circuit at the PCM connector between terminal/pin-4 and terminal/pin-11 with an ohmmeter.