Conditions for Setting the DTC

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The VCIM detects an open in the cellular microphone signal circuit or drain wire circuit.
The VCIM detects a short to voltage in the cellular microphone signal circuit.
The above conditions are present for greater than 10 seconds.