Rear Video System On - VCP and Radio Playing Mode

WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

Assumption:

The ignition switch is in the ACC or RUN position.
The radio is on.
The rear seat audio (RSA) module is off.
The video screen is down.
The video cassette player (VCP) is playing.

When the auxiliary module senses that the radio is on, the rear speakers are muted.