Chevrolet Cab & Chassis C3500 (1989-2000) 4.3l (vin z), data link connector circuit

BLK/WHT WIRE DATA LINK CONNECTOR DIAGNOSTIC REQUEST DIAGNOSTIC TEST FOUR-WHEEL ANTI-LOCK BRAKE MODULE (NEAR MASTER CYLINDER) FUEL PUMP FUEL PUMP PRIME FUEL PUMP RELAY GRY WIRE ORG/ WIRE POWERTRAIN CONTROL MODULE (UNDER RIGHT END OF I/P) RED WIRE SERIAL DATA TAN/WHT WIRE WHT/BLK WIRE