SERVICE MANUAL UPDATE SEC. 6E3 (CODE 12 FLASHING EXPLANATION)

SUBJECT EXPLANATION OF CODE 12 FLASHING

MODELS/YEARS 1990-1993 CUTLASS CALAIS, ACHIEVA CUTLASS CIERA/CRUISER WITH 3300 (VIN N) ENGINE

This bulletin cancels and supersedes Service Manual Update 92-U-27 which should be discarded.

When no trouble codes are stored in the ECM memory and the system is requested to flash codes, Code 12 will flash three times, THERE WILL BE A PAUSE OF APPROXIMATELY 30 SECONDS, and then Code 12 will flash again. The length of the pause is normal for this system. DO NOT replace the ECM or PROM (MEMCAL) to correct this characteristic.

If a trouble code is stored in memory, Code 12 will flash three times, the trouble code(s) will flash three times, THERE WILL BE A PAUSE OF APPROXIMATELY 30 SECONDS, and then Code 12 will flash again. This is normal operation.

If trouble codes are cleared or the ECM has been disconnected and then reconnected and code flashing is requested BEFORE STARTING THE ENGINE, Code 12 will flash continuously.

It is suggested that a scan tool be used to check for trouble codes to avoid confusion.

Please mark a reference to this bulletin on page 6E3-A-l1 of your copies of the 1990, 1991, 1992, and 1993 Cutlass Calais, Achieva, Cutlass Ciera/Cruiser Service Manuals.

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.