Circuit/System Verification
- Verify that DTC P0641 or P0651 is not set.
- Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust
.
- Verify that the engine is in good mechanical condition. Refer to Symptoms - Engine Mechanical
.
- Ignition OFF for 90 seconds, determine the current vehicle testing altitude.
- Ignition ON, engine OFF, observe the scan tool MAP Sensor parameter. Compare the parameter to the Altitude Versus Barometric Pressure
table. The MAP Sensor parameter should be within the specified range indicated in the table.
- Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions. The readings should be within 5 kPa of the known good vehicle.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.