Visual/Physical Inspection

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Inspect for aftermarket devices which could affect the operation of the Instrument Cluster or Audible Warning Systems. Refer to Checking Aftermarket Accessories in Wiring Systems.
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Inspect the applicable reservoir for the proper fluid level related to the indicator or message.
Verify that the indicators work properly during the displays test.