GMC Cab & Chassis K2500 (1989-2000) 4.3l (vin z), transmission circuit, 4l80-e

1-2 SHIFT SOL 2-3 SHIFT SOL BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE ECM IGN FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FUSIBLE LINK GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START HOT IN START OR RUN FUSE BLOCK TRANS FUSE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE PCM TRANS SHIFT SOL B PCM TRANS SHIFT SOL A PNK WIRE PNK/BLK WIRE PNK/WHT WIRE POWERTRAIN CONTROL MODULE (PCM) (UNDER RIGHT END OF I/P) PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) SYSTEM GROUND DLC THROTTLE POSITION SENS SENSOR GROUND SENSOR GROUND TCC SOL TCC SOL CTRL RANGE SIGNAL "B" RANGE SIGNAL "C" TCC/BRAKE SWITCH (TOP OF BRAKE PEDAL) THROTTLE POSITION SENSOR (RIGHT SIDE OF TBI) TRANS FLUID TEMP (TFT) SENSOR TRANS FLUID TEMP SIG ECT SIG VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE