A/C CONTROLS WARM AFTER VEHICLE IS PARKED 2-5 HOURS

SUBJECT: A/C BLOWS WARM AIR AFTER VEHICLE IS PARKED 2-5 HOURS INSTALL NEW PROGRAMMER

MODELS/YEARS: 1991 NINETY-EIGHT

CONDITION: Owners of some 1991 Ninety-Eight Models may experience a condition where the HVAC does not immediately control the temperature properly. This normally occurs after the vehicle is driven in the morning then parked during cool ambient temperatures. Returning to the vehicle at mid-day, less than five hours later, when the ambient temperature is warmer by twenty degrees or more, the A/C will not properly cool the vehicle.

CAUSE: Programmers with software versions 01 through 06 prohibit the outside temperature from updating until five hours have elapsed after the ignition is turned off. Vehicles with these software versions must be driven above 10 mph for the outside temperature display to update. It may take up to ten minutes to fully update at 50 mph.

CORRECTION: A new programmer, P/N 16165978, has been released for service. The new software version will be 07. This programmer will allow the temperature display to update after the ignition has been off for 2 1/2 hours minimizing the effect of rising ambient temperatures.

Parts are currently available from GMSPO.

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.