Chart C-1D, Pressure Sensor

NOTE: Test numbers refer to test numbers on diagnostic chart.

With ignition on and engine not running, the pressure sensor functions as a BARO sensor.
If pressure sensor wiring and ECM are okay, the voltage will drop, simulating a change in altitude. If wiring is open or shorted to ground, "Scan" tester reading will always stay high.

Fig 1: Chart C-1D, Pressure Sensor Ckt Diag.

Fig 2: Chart C-1D, Pressure Sensor Flow Chart