A/C COMPRESSOR OPERATION DURING START - UP
SUBJECT: A/C COMPRESSOR OPERATION DURING START-UP TO CONTROL RPM FLARE ON VEHICLES EQUIPPED WITH THE 3800 T.P.I. ENGINE (VIN L)
MODELS AFFECTED: 1991 PARK AVENUE ULTRA WITH 3800 T.P.I. ENGINE (VIN L) BUILT PRIOR TO M1626149 1990-91 REGAL MODELS, FEDERAL EMISSIONS - BUILT PRIOR TO M1813629 1990-91 REGAL MODELS, CALIFORNIA EMISSIONS, BUILT PRIOR TO M1813961
From start of production, the above vehicles with listed serial numbers, allows during each ignition cycle the A/C compressor to engage, up to five seconds, to minimize engine RPM flare with the A/C mode switch in the on or off position. A/C compressor engagement during start-up on vehicles that have a sudden loss of refrigerant or have lost all the refrigerant over a period of time, may contribute to an A/C compressor failure.
If a technician is servicing the A/C system on a vehicle built prior to the breakpoint listed, it is recommended that a new calibration mem-cal be installed, in conjunction with the A/C system repairs.
The new calibration will eliminate A/C compressor operation during engine start-up.
The mem-cals are currently available through GMSPO under the following part numbers. SCANNER ID IF APPLI- AXLE MEM-CAL BROAD- SERVICE YEAR & MODEL CATION RATIO INSTALLED CAST PART # -------------------- -------- -------- --------- ---- -------- 1991 Park Ave./Ultra Fed. F17/2.84 9994 AXDH 16160178 1991 Park Ave./Ultra Calif. F17/2.84 0004 AXDJ 16160173 1991 Park Ave./Ultra Fed. opt. 3.06* 0014 AXDK 16160168 1991 Park Ave./Ultra Calif. opt. 3.06* 0024 AXDL 16160163 1990-91 Regal Fed. All 0044 AXDN 16160153 1990-91 Regal Calif. All 0054 AXDP 16160148
* Part of Option Package Y56 or V92
IMPORTANT: The new calibration mem - cals are currently being used in production. Verify if this mem-cal is already installed by the scanner I.D.
WARRANTY INFORMATION:
Use applicable Labor Time Guide Operation Number and Time.
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.
