Circuit/System Verification

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.
Use the scan tool and compare the MAP Sensor parameter at ignition ON, with the engine OFF, to the Altitude vs Barometric Pressure table. Refer to Altitude Versus Barometric Pressure .