Computer & Controls - Explanation of Code 12 Flashing

Bulletin:
93-6E-5

Date:
Nov.'92

Ref.No.:
93-39-6E

Corp.Ref.No.:
116523R

SUBJECT:
SERVICE MANUAL UPDATE - SECTION 6E3 - EXPLANATION OF CODE 12 FLASHING

MODELS AFFECTED:
1990-93 CENTURY AND SKYLARK WITH 3300 ENGINE (VIN N)


This bulletin has been revised to include 1990-93 Skylark models and 1993 Century models equipped with the 3300 (VIN N) engine.

This bulletin applies to 1990-93 Century and Skylark models equipped with a 3.3L (VIN N) engine only.

When no trouble codes are stored in the ECM's 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 ECMs or MEMCALs to try 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 Century and Skylark Service Manuals.