Computer & Controls - Explanation of Code 12 Flashing
NUMBER: 93-U-08CORP.REF.NO: 116523R
DATE: November 1992
SECTION: 6E3
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-11 of your copies of the 1990, 1991, 1992, and 1993 Cutlass Calais, Achieva, Cutlass Ciera/Cruiser Service Manuals.