Circuit/System Verification
- If P0641 or P0651 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Verify the integrity of the entire air induction system by inspecting for the following conditions:
- Any damage to or hairline fractures of, the MAP sensor housing
- Loose or improper installation
- Any vacuum leak
- Verify that restrictions do not exist in the MAP sensor port or vacuum source.
- Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude vs Barometric Pressure table. Refer to Altitude Versus Barometric Pressure .
- Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.
IMPORTANT:
The MAP sensor 5-volt reference circuit is spliced to other components of the vehicle.