1986 HEATEIR MODULE VIN PRODUCTION DIV CODE USAGE COL N0 03055105 12 B E XC HTR C4 5 A C 1 03058397 1 B W HTR C41 C46 2 03055104 123 G E XC A C 3 03055101 12 T E XC A C 4 1991 GENERAL MOTORS SERVICE PARTS OPERATIONS CHEVROLET 17W 6 91 asu 8 845