This sensor is a pressure sensitive variable resistor. It measures the changes in the intake manifold pressure, which result from engine load and speed changes, and converts to a voltage output. This sensor is used to measure the barometric pressure at start up, and under certain conditions, allows the ECM to automatically adjust for different altitudes. The ECM supplies 5 volts to the sensor and monitors the voltage on a signal line. The sensor provides a path to ground through its variable resistor. The sensor input affects fuel delivery and ignition timing controls in the ECM.
Removal & Installation
- Disconnect the negative battery cable.
- Disconnect the connector from the sensor.
- Remove the sensor retaining screws.
- Remove the sensor from its mounting.
- Installation is the reverse of the removal procedure.
- Turn the ignition switch ON.
- Measure the voltage between terminal 1 (sensor output) and terminal 4 (sensor ground).
- Specification should be 4-5 volts.
- If not within specification, replace the sensor.