LACK OF POWER AT HIGH SPEED (DIAGNOSIS/PROM)

VEHICLES AFFECTED: 1989 B-CAR WITH 5.7L (VIN CODE 7)

Some 1989 B-cars with the 5.7L V8 engine may exhibit lack of power at high speeds. Additionally, these vehicles MUST be operated in 4th gear (NOT 3rd gear) at high speeds to maximize powertrain performance. If the vehicle does not shift into 4th gear at Wide Open Throttle, refer to bulletin # 89-7700-107 for important information concerning a 3-4 upshift valve package.

If the vehicle performance cannot be improved by following normal diagnostic procedures, the following PROM may be used along with the 3-4 upshift valve package per the above bulletin.

Engine Trans New Service PROM New Scanner ID Broadcast Code ------ ----- ---------------- -------------- ----------------- 5.7L Auto 16144294 4301 ATJP

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.