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

OnStar® Component Locations


Object Number: 623162  Size: MF
(1)Cellular Antenna
(2)OnStar® Microphone
(3)Global Positioning System (GPS)
(4)Body Wiring Junction Block
(5)Vehicle Communication Unit
(6)Keypad
(7)Vehicle Interface Unit
Figure 2:

Cell Phone Wiring Harness to Body Wiring Junction Block


Object Number: 615945  Size: MF
(1)Body Wiring Harness Junction Block
(2)C3
(3)Cell Phone Harness
Figure 3:

Cell Phone Harness to Roof Front Header


Object Number: 615937  Size: MF
(1)Front Side Door Opening Reinforcement
(2)Cell Phone Harness
(3)Body Side Inner Panel
Figure 4:

OnStar® Vehicle Interface Unit (VIU)


Object Number: 623205  Size: MF
(1)OnStar® (Vehicle Interface Unit)
(2)VIU Connector C-2 (Blue)
(3)VIU Connector C-1 (Red)
(4)I/P Panel-RH
Figure 5:

Onstar Vehicle Communication Unit (VCU)


Object Number: 623169  Size: MF
(1)IP Support Bracket
(2)Vehicle Communication Unit (VCU)
(3)Vehicle Communication Unit (VCU) Connector
(4)C248
(5)Vehicle Communication Unit (VCU) Harness
Figure 6:

GPS Antenna


Object Number: 623207  Size: MF
(1)Global Positioning System (GPS) Harness
(2)GPS Connector
(3)GPS Antenna
Figure 7:

Overhead Console -- OnStar® Components


Object Number: 623185  Size: MF
(1)Inline Connector C211
(2)Overhead Reading Lamps
(3)OnStar® Microphone
Figure 8:

Airbag Disabling Switch


Object Number: 623177  Size: MF
(1)OnStar® Communications Keypad
(2)Airbag Disabling Switch Connector
(3)Airbag Disabling Switch
Figure 9:

OnStar® Keypad


Object Number: 623182  Size: MF
(1)OnStar® Keypad Connector
(2)OnStar® Keypad
Figure 10:

Behind the Center of the I/P -- Radio Connections


Object Number: 623166  Size: MF
(1)Radio
(2)I/P Connector to Radio Connector C-3
(3)Jumper Connector, With Remote CD