Circuit/System Verification

WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Verify that DTC P0641 or P0651 is not set.
- If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P0641 or P0651 for further diagnosis.
Verify restrictions do not exist in the exhaust system. Refer to Restricted Exhaust .
Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 1,700-3,200 Hz depending on the ECT.
A wide open throttle (WOT) acceleration from a stop should cause the MAF Sensor parameter on the scan tool to increase rapidly. This increase should be from 2-6 g/s at idle to greater than 100 g/s at the time of the 1-2 shift.
Use the scan tool and compare the MAF Sensor parameter to a known good vehicle under various operating conditions.
Ignition ON, observe the MAP sensor pressure parameter and compare to the Altitude Versus Barometric Pressure table. The MAP sensor reading should be within the specified range.
- If the MAP sensor pressure is not within the specified range, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P0106 for further diagnosis.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.