Visual/Physical Inspection

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Inspect for aftermarket devices which may affect the operation of the instrument panel cluster. Refer to Checking Aftermarket Accessories in Wiring Systems.
Inspect for aftermarket devices which may affect the operation of the hydraulic brake system.
Inspect the easily accessible or visible system components for obvious damage or conditions which may cause the symptom.