GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Pickup - 4WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Cellular Communication Component Views
Figure 1:

Vehicle Communication Unit (VIU) & Vehicle Interface Unit (VIU)
Object Number: 512198 Size: MF
(1)IP Dash, Passenger Side
(2)Crossbody Harness
(3)Vehicle Interface Unit (VIU)
(4)C250
(5)C251
(6)C252
(7)GPS Antenna Cable
(8)Vehicle Communications Unit (VCU)
Figure 2:

Cellular Phone Wiring
Object Number: 312740 Size: MF
(1)Cellular Phone Connector
(2)Cellular Phone
(3)Heated Seat Switch, RR
(4)Heated Seat Switch, LR
(5)Modem/Fax Line
(6)Celluluar Phone Connection
Figure 3:

Overhead Console Wiring, Escalade
Object Number: 512202 Size: MF
(1)C315
(2)Overhead Console
(3)C306
(4)Microphone Connector
(5)Microphone
(6)Keypad Connector