Component Test

Barometric Pressure Sensor Circuit:

1. Connect a voltmeter between terminals 4 and 5 of the AFS Sensor connector.
Terminal 5: Barometric sensor output
Terminal 4: sensor ground
Terminal 3: sensor 5v power

Voltage (W/ key on and engine off)
- At sea level
Approximately 4.0 volts.
- At 2,000 ft.
Approximately 3.75 volts.
- At 4,000 ft.
Approximately 3.50 volts.
- At 6,000 ft.
Approximately 3.25 volts.

2. Warm the engine and bring it to a normal idle.

Barometric Pressure Sensor Test:

3. Slowly cover about half of the air cleaner air intake, observing the change in voltage. As pressure falls (vacuum increases), you should observe a drop in voltage.


If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.

If the same trouble code reoccurs, it is possible that there is an intermittent failure of the component or the ECM. Check for looseness at all harness junctions and test for an intermittent failure.