Symptoms Verification: Notes

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.

Before using the Symptom tables, perform the following inspections:

Ensure that the engine control module (ECM) and malfunction indicator lamp (MIL) are operating correctly.
Ensure that there are no DTCs that are stored.
Ensure that the scan tool data is within a normal operating range.
Verify the customer concern.
Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.