GENERAL MOTORS HAS DETERMINED THAT CERTAIN 1995 BUICK PARK AVENUE AND RIVIERA MODEL VEHICLES EQUIPPED WITH A 3800 SERIES II ENGINE (L36) MAY HAVE A DECELERATION STALL UNDER LIMITED CONDITIONS. THIS COULD RESULT IN A LOSS OF POWER STEERING ASSIST, GENERATOR AND POWER BRAKING ASSIST. TO PREVENT THIS CONDITION FROM OCCURRING, DEALERS ARE TO REPLACE SUSPECT MEM-CAL OF THE POWERTRAIN CONTROL MODULE (PCM) WITH A MEM-CAL OF AN IMPROVED DESIGN. *TW