GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Below RH Rear of Vehicle


Object Number: 228017  Size: LF
(1)RH Rear Rail
(2)Automatic Level Control Sensor
(3)Automatic Level Control Compressor
Figure 2:

Rear Compartment, Right Side (Pontiac)


Object Number: 228018  Size: LF
(1)Automatic Level Control Relay
(2)Inflator Air Solenoid Valve
(3)P403