Retained Accessory Power

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Retained Accessory Power Block Diagram

Courtesy of GENERAL MOTORS COMPANY

Callout	Component Name
K84	K84 Keyless Entry Control Module
A11	A11 Radio
KR76A	KR76A Retained Accessory Power Relay 1
KR76B	KR76B Retained Accessory Power Relay 2
X81	X81 Accessory Power Receptacle - 110V AC
X81B	X81B Accessory Power Receptacle - 220V AC
P2	P2 Transmission Shift Lever Position Indicator
K9	K9 Body Control Module
K73	K73 Telematics Communication Interface Control Module

The body control module (BCM) monitors the ignition position, battery condition, and each door ajar/open switch status to determine whether the retained accessory power should be initiated or terminated. Retained accessory power is controlled by two different methods; retained accessory power relay coil control circuit and serial data. Some modules receive a retained accessory power message from the BCM over the serial data circuits. Serial data controlled retained accessory power is deactivated as required by their modules retained accessory power mode operation. Other subsystems may be activated directly by the BCM or by the BCM through a relay. Components and systems that are active in retained accessory power are also activated anytime the ignition is any position other than OFF regardless of the door switch signals.