The absolute pressure sensor is connected to the MAP/BARO switch solenoid valve by a hose. The sensor detects ambient barometric pressure and intake manifold pressure and sends the voltage signal to the ECM. As the pressure increases, the voltage rises.
- Remove the sensor with its harness connector connected.
- Remove the hose from the pressure sensor.
- Turn the ignition switch on and check the output voltage between the terminal 64 and engine ground. The voltage should be 3.2-4.8 volts.
Use the pump to apply vacuum of 7.8 in. hg to the sensor and check the output voltage. It should be 1.0-1.4 volts lower than the value measured in the above step.
WARNINGAlways calibrate the vacuum pump gauge when first using it.
WARNINGDo not apply less than 27.5 in. hg or more than 29.9 in. hg of pressure.
- If these results are yielded, replace the manifold absolute pressure sensor.