ON-BOARD DIAGNOSTIC SYSTEM IMPROVEMENTS. Chevrolet Lumina 1997

SUBJECT: ON-BOARD DIAGNOSTIC (OBD) SYSTEM IMPROVEMENTS (RE-FLASH CALIBRATION)

MODELS: 1997 CHEVROLET LUMINA, MONTE CARLO WITH 3100 V6 ENGINE (VIN M - RPO L82) WITH AUTOMATIC TRANSMISSION

VIN BREAKPOINTS: START OF PRODUCTION (SOP) TO END OF PRODUCTION (EOP)

WHILE THE SUBJECT VEHICLE HAS BEEN CERTIFIED AS COMPLYING WITH THE APPLICABLE U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA) AND CALIFORNIA AIR RESOURCES BOARD (CARB) ON-BOARD DIAGNOSTIC (OBD) REQUIREMENTS, WE HAVE IDENTIFIED AN OBD SYSTEM IMPROVEMENT THAT SHOULD BE IMPLEMENTED WHENEVER PRACTICAL.

CONDITION: 1997 CHEVROLET LUMINA AND MONTE CARLO 3.1L V6 ENGINE EQUIPPED VEHICLES MISFIRE DIAGNOSTICS HAVE BEEN INADVERTENTLY DISABLED WHEN THE FUEL SYSTEM'S FUEL LEVEL SENSOR FAILS IN THE EMPTY POSITION.

CAUSE: THE VEHICLES WERE RELEASED WITH SOFTWARE WHICH INADVERTENTLY DISABLED THE MISFIRE DIAGNOSTICS WHEN THE FUEL SYSTEM'S FUEL LEVEL SENSOR FAILS IN THE EMPTY POSITION.

CORRECTION: USE A TECH II TO VERIFY WHAT SOFTWARE IS PROGRAMMED INTO THE VEHICLE'S POWERTRAIN CONTROL MODULE (PCM). IF THE IMPROVED SOFTWARE HAS NOT BEEN INSTALLED, RE-PROGRAM/RE-FLASH WITH THE UPDATED SOFTWARE. REFER TO THE CALIBRATION TABLE FOR THE APPROPRIATE CALIBRATION CHANGE.

CALIBRATION INFORMATION:

THE CALIBRATIONS LISTED ARE FLASH CALIBRATIONS AND NOT AVAILABLE FROM GMSPO. SERVICE FLASH CALIBRATIONS ARE AVAILABLE STARTING WITH THE 1998 CD #3.

MODEL EMISSION TYPE CALIBRATION

W USA NATIONWIDE 09355514

W CANADIAN/UNLEADED FUEL EXPORT 09355524

W USA NATIONWIDE POLICE/TAXI 09355544

W CANADIAN UNLEADED FUEL POLICE/TAXI 09355554

IMPORTANT: INFORM CUSTOMERS THAT THIS WORK IS BEING PERFORMED ON THEIR VEHICLES TO IMPROVE ON-BOARD DIAGNOSTIC SYSTEM OPERATION AND DOES NOT AFFECT VEHICLE DURABILITY, RELIABILITY, OR PERFORMANCE.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION: J-6355 LABOR TIME: USE PUBLISHED LABOR TIME

IMPORTANT: THIS LABOR OPERATION IS COVERED UNDER EITHER THE FEDERAL OR CALIFORNIA EMISSION CONTROL SYSTEM WARRANTY (WHICHEVER APPLIES) OR THE ôBUMPER- TO-BUMPERö COVERAGE IN THE NEW VEHICLE LIMITED WARRANTY. THE WARRANTY WITH THE BROADEST COVERAGE APPLIES.

FIGURES: 00 ATTACHMENTS: 00

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.