Circuit Description
WARNING: This page is about a different car, the 2002 GMC Safari and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is in the UNLOCK position, certain class 2 messages do not transmit. The instrument panel cluster (IPC) suspends the operation of the indicators and the gages that are dependent on these messages until the ignition switch is no longer in the UNLOCK position.