GM Service Manual Online
For 1990-2009 cars only

When the rear compartment lid release switch is pressed, ground is applied on CKT 1576 (BLK) at terminal D5 connector 1 of the instrument panel integration module (IPM). The IPM will send a message via the class 2 data line to the rear interface module (RIM). The RIM applies ground to CKT 1344 (LT BLU), with the valet switch in the ACCESS position, voltage is applied from the ALDL fuse 4, through the TRK REL relay coil. The relay energizes, the contacts close and voltage is applied from the BODY fuse to the rear compartment lid release solenoid. The solenoid is connected to ground G402 via CKT 850 (BLK).