Test Description

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, and 2002 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

The number below refers to the step number in the diagnostic procedures.

5

This test will determine the ability of the engine controller and IAC valve circuits to control the IAC valve.

7

This test will determine the ability of the PCM to provide the IAC circuits with a ground. On a normal operating system, the test lamp should not flash while the IAC counts are incrementing.