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

LR of Cargo Area


Object Number: 1413129  Size: LF
(1)Rear Parking Assist (RPA) Module
Figure 2:

Rear Bumper


Object Number: 1277021  Size: LF
(1)Rear Parking Assist (RPA) Object Sensor - Right Rear Corner
(2)Rear Parking Assist (RPA) Object Sensor - Right Rear Middle
(3)Rear Parking Assist (RPA) Object Sensor - Left Rear Middle
(4)Rear Parking Assist (RPA) Object Sensor - Left Rear Corner
Figure 3:

Headliner


Object Number: 1374461  Size: LF
(1)Blower Motor Switch - Front Auxiliary (C57)
(2)Blower Motor Switch - Rear Auxiliary (C57)
(3)Courtesy/Reading Lamp - Rear
(4)Rear Parking Assist (RPA) Display
(5)Courtesy/Reading Lamp - Center
(6)Courtesy/Reading Lamp - Front
Figure 4:

Left Rear of Vehicle Behind the Trim Panel


Object Number: 1276922  Size: LF
(1)Audio Amplifier
(2)Rear Parking Assist (RPA) Diagnostic Connector--If the vehicle is equipped with a power liftgate, the RPA diagnostic connector is behind the liftgate actuator.