BECAUSE OF CHANGES MADE IN THE ALCL DATA STREAM ON THE NEW 1982 1/2 TWO (2) BOARD ELECTRONIC CONTROL MODULES, A MODIFIED PROCEDURE MUST BE USED WHEN OPERATING THE 1982 ALCL SCANNER ON THIS SYSTEM. THE SYSTEM DIFFERS FROM THE EARLIER 1982 EFI SYSTEM IN THAT DATA IS SENT TO THE SCANNER IN SPECIAL OR BACK-UP MODES, THUS WHEN THE OPEN MODE IS SELECTED, NO DATA IS DISPLAYED. THE PROCEDURE IS AS FOLLOWS: 1.IGNITION SWITCH OFF. 2.PLUG THE SCANNER INTO THE CIGARETTE LIGHTER AND INTO THE ALCL CONNECTOR. 3.PLACE THE ROTARY SWITCH IN THE MODE POSITION. 4.WHILE THE MESSAGE "NO ALCL" IS SHOWING ON THE DISPLAY, TURN ON THE IGNITION SWITCH. THE DISPLAY SHOULD GO BLANK AND REMAIN BLANK. 5.PLACE THE ECM INTO THE SPECIAL MODE BY DEPRESSING THE MODE BUTTON ONE (1) TIME. THE DISPLAY WILL THEN SHOW "OPEN YES" AND THEN "SPEC YES". THE SCANNER WILL NOW DISPLAY ALL DATA IN EITHER THE SPECIAL OR BACK-UP MODE AND NO DATA IN THE OPEN MODE. THIS SPECIAL PROCEDURE WILL NOT BE NECESSARY WHEN THE 1982 SCANNERS ARE RETURNED TO MICRO-PROCESSORS SYSTEMS, INC., THIS SUMMER; TO BE UPDATED FOR 1983.
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.