MANUAL UPDATE-SECTION 6E DRIVEABILITY AND EMISSION

VEHICLES AFFECTED: 1989 3300 (VIN N) A,N SERIES

*This bulletin has been revised to add reference to Section "8A" and to specify C3I connector "M" circuit numbers.

Several instances of alternate wire colours going to the C3I module on 1989 "A" and "N" vehicles equipped with a 3300 (VIN N) engine have been reported. This would effect wire colours on diagnostic Charts A-3, C-4H-1, C-4H-2, and Code 42 Chart found in Section 6E "Driveability and Emissions" of the Service Manual. It would also effect the wire colours on the ECM Wiring Diagrams at the front of Section 6E3-A "Driveability and Emissions" and Section 8A "Electrical Diagnosis".

On vehicles that have the alternate wire colours, the circuits remain the same. If the colours do not match that of the Service Manual, they may be as follows:

C3I Connector Circuit No. Original Colour Alternate Colour ------------- ----------- --------------- ---------------- A 423 WHT WHT B 424 TAN/BLK TAN/BLK C 430 PPL/WHT PPL/WHT D 453 BLK/RED BLK/RED E 121 WHT WHT F 646 LT BLU/WHT WHT/BLK G 645 GRY/RED DK BLU/WHT H 644 WHT/BLK LT BLU/WHT K 643 DK BLU/WHT GRY/RED N car only M 239 PNK/WHT PNK/BLK A car only M 839 PNK/WHT PNK/BLK

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.