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

Near the Brake Booster


Object Number: 1863194  Size: LF
(1)Brake Fluid Level Switch
(2)Left Fender
(3)G103
(4)G101
(5)G115
(6)G105
(7)Electronic Brake Control Module (EBCM)
(8)Brake Booster Vacuum Sensor
Figure 2:

Below the Driver Side I/P


Object Number: 1863186  Size: LF
(1)Audio Amplifier (UQA or UQG or UQS)
(2)Body Control Module (BCM)
(3)Brake Pedal Position Sensor
(4)Accelerator Pedal Position (APP) Sensor
(5)G301
(6)Park Brake Switch