Circuit/System Verification
IMPORTANT:
Verify that the engine is in good mechanical condition before continuing with this diagnostic.
IMPORTANT:
If you cannot duplicate the condition, 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.
- Verify the integrity of the air induction system by inspecting for the following conditions:
- Any damaged components
- Loose or improper installation
- Improperly routed vacuum hoses
- Any vacuum leak
- Verify there are no restrictions or leaks in the MAP sensor vacuum source.
- Verify there are no restrictions in the exhaust system. Refer to Restricted Exhaust .
- A skewed or stuck engine coolant temperature (ECT) or IAT will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to Temperature vs Resistance .
- The BARO that is used by the ECM to calculate the air flow models is initially based on the MAP sensor at ignition ON. When the engine is running, the ECM will continually update the BARO value near wide open throttle (WOT) using the MAP sensor and a calculation. A skewed MAP sensor will cause the BARO value to be inaccurate. Use a scan tool and compare the BARO parameter with the ignition ON to the Altitude vs. Barometric Pressure table. Refer to Altitude vs Barometric Pressure .
- A skewed MAP sensor will also cause the first and second intake manifold models to disagree with the actual MAP sensor measurements. Use a scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions.