Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Extended use of extremely high volume, especially in warm weather conditions, may induce this DTC. Under these conditions it may be normal for this DTC to set to prevent permanent damage to the amplifier circuitry. If DTC persists without excessive volume, replace the amplifier.