GM Service Manual Online
For 1990-2009 cars only

IDLE SPEED HUNTING NEW PROM P/N

TO IMPROVE IDLE INSTABILITY ("HUNTING") ON 1981 2.5 L4 ENGINES, THE PROCEDURES IN DEALER TECHNICAL BULLETIN 81-T-7 SHOULD BE FOLLOWED. IF, AFTER PERFORMING THE ADJUSTMENTS DESCRIBED IN THIS BULLETIN, AN IDLE INSTABILITY CONDITION STILL EXISTS, A NEW PROM IS AVAILABLE TO REDUCE "HUNTING" CHARACTERISTICS. THE NEW PROM PART NUMBER IS 1225280 AND IS BEING USED IN PRODUCTION. A BROADCAST CODE OF AAD WILL INDICATE THE ECM IS EQUIPPED WITH THE NEW PROM.

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.