GMC. TRUCK SERVICE BULLETINS NUMBERING SYS. GROUP CODE INFO

MODELS: ALL MODEL YEARS

Effective with the start of the 1990 model year GMC Truck has revised the service bulletin numbering system and Group (UPC) Codes. These changes are a result of dealer responses and feedback and are designed to improve the overall efficiency and quality of the service bulletins.

NUMBERING SYSTEM

New bulletins continue to be numbered according to the latest model year of the vehicles involved in the bulletin. A bulletin covering 1986-1990 model year vehicles will become a 90 bulletin. The "T" designator in GMC Truck bulletins bas been replaced with the Group (UPC) listing to aid dealers in keeping accurate files. Bulletins will remain numbered in a sequential fasbion regardless of UPC Code in order for dealers to keep track of missing bulletins. The example below shows the use of the new numbering system.

EXAMPLE:

------- 90 OA 100

(1990 MODEL) GROUP OA GENERAL BULLETIN NUMBER

YEAR INFORMATION 100 FOR 1990 MODELYEAR

GROUP/UPC CODES

Although there are minor changes in the Group (UPC) listing, your current divider tabs and binders will still be usable. The new bulletin will be grouped according to the UPC Codes listed on the back of this bulletin, which coincide with those currently used in Truck Service Manuals.

OA GENERAL INFORMATION OB MAINTENANCE ANTD LUBRICATION 1A HEATING AND VENTILATION 1B AIR CONDITIONING 2 FRAME-BUMPER-SHEET METAL 3 DIAGNOSIS STEERING SUSPENSION WHEELS AND TIRES 3A FRONT ALIGNMENT 3B STEERING 3C FRONT SUSPENSION 3D REAR SUSPENSION 3E WHEELS AND TIRES 4A PROPELLER SHAFT 4B REAR AXLE 4C FRONT AXLE 5 BRAKES 5E ANTI-LOCK BRAKES 6 ENGINE DIAGNOSIS 6A ENGINE MECHANICAL 6B ENGINE COOLING 6C ENGINE FUEL 6D ENGINE ELECTRICAL 6E ENGINE ELECTRICAL 6F ENGINE EXHAUST 7A AUTOMATIC TRANSMISSION 7B MANUAL TRANSMISSION 7C CLUTCH 7D TRANSFER CASE 8A CAB ELECTRICAL 8B CHASSIS ELECTRICAL 8C INSTRUMENT PANEL AND GAGES 8D WINDSHIELD WIPER/WASHER SYSTEM 9 ACCESSORIES 9A AUDIO SYSTEMS 10 BODY SECTION 10-A1 DOORS 10-A2 SEATS AND SEAT BELTS 10-A3 GLASS WIRING DIAGRAMS

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.