GM Service Manual Online
For 1990-2009 cars only
Fuel Door Release Switch (IPM): The scan tool displays the on/off state of the fuel door release switch input to the IPM.

Trunk Release Switch (IPM): The scan tool displays the on/off state of the rear compartment release switch input to the IPM.

Fuel Door Release Output (RIM): The scan tool displays the state of the RIM fuel door release output control.

Trunk Release Output (RIM): The scan tool displays the state of the RIM rear compartment lid release output control.