Some owners of 2010-2011 Buick LaCrosse vehicles equipped with a 3.6L V6 engine built prior to VIN BF358708 may comment that the MIL is illuminated within the first 60 seconds of operation after a cold start. A revised calibration has been developed to address this condition. No driveability concern is present, and the technician may find DTC P0300 through P0306 (random misfire counts).

Reprogram the ECM with updated calibration files using the TIS2Web Service Programming System application. Select SEQ Programming sequence ECM.TCM from the supported controllers screen. Refer to Si and Service Programming System for programming instructions if required.

Calibrations include multiple updates. Confirm that the newest calibration includes the following description: “P0300 cold start, low ambient temperature – low misfire counts, first 60 seconds.” This calibration should only be used to repair vehicles that have the subject condition.

Reprogram the ECM with the software now available in TIS2WEB using the service programming system (SPS).