GMC Cab & Chassis Sierra 3500 (2004-2007) Computer data lines circuit, base & up-level

3 2 1 PPL BLK WIRE BLK/WHT WIRE BODY CONTROL MODULE (ON LOWER LEFT SIDE OF DASH, BELOW STEERING COLUMN) BRN WIRE BRN/WHT WIRE CIG LTR FUSE DATA LINK CONNECTOR (DLC) (UNDER LEFT SIDE OF DASH, BELOW STEERING COLUMN) DIGITAL RADIO RECEIVER DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DRIVER DOOR MODULE (DDM) (IN LEFT FRONT DOOR) ELECTRONIC BRAKE CONTROL MODULE (EBCM) (ON LEFT SIDE OF INNER FRAME) EXCEPT 6.6L VIN 2 6.6L VIN 2 FRONT PASSENGER DOOR MODULE (FPDM) (IN RIGHT FRONT DOOR) GROUND DISTRIBUTION SYSTEM GRY WIRE HOT AT ALL TIMES HVAC CONTROL MODULE (BEHIND CENTER OF DASH) I/P RELAY BLOCK INFLATABLE RESTRAINT SENSING/DIAGNOSTIC MODULE (UNDER LEFT FRONT SEAT) INSTRUMENT PANEL CLUSTER (IPC) LEFT I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE MEMORY SEAT MODULE (UNDERSIDE OF DRIVER SEAT) NEAR KICK PANEL) ORG/ WIRE PNK WIRE POWER DISTRIBUTION SYSTEM RADIO (AT CENTER OF DASH) REAR SEAT AUDIO (RSA) CONTROLLER (UNDER REAR OF CENTER CONSOLE) REAR SEAT ENTERTAINMENT (RSE) ASSEMBLY (AT CENTER OF HEADLINER) REMOTE PLAYBACK DEVICE-CD PLAYER (CENTER OF DASH, BELOW RADIO) RIGHT I/P FUSE BLOCK (UNDER RIGHT SIDE OF DASH) TAN WIRE TRANSFER CASE SHIFT CONTROL MODULE (BEHIND HEADLAMP SWITCH) TRANSMISSION CONTROL MODULE (AT LEFT FRONT OF ENG COMPT) UNDERHOOD FUSE BLOCK (AT LEFT SIDE OF ENGINE COMPT, NEAR BATTERY) VEHICLE COMMUNICATION INTERFACE MODULE (VCIM) (BEHIND PASSENGER AIR BAG MODULE) WHT WIRE YEL WIRE