GM Service Manual Online
For 1990-2009 cars only

The following components continuously supply voltage to the vehicle interface unit (VIU):

    • The RDO BATT fuse 19
    • CKT 340 (ORN)
    • The inline fuse

Voltage is supplied to the vehicle interface unit (VIU) through the RDO IGN fuse 24 and CKT 1301 (DK GRN), when the ignition switch is in the ACCY position and the RUN position.

The following components provide the vehicle interface unit (VIU) ground path:

    • CKT 1850 (BLK)
    • SP202
    • G200
    • G201