For 1990-2009 cars

# SMU-SECTION 6E-REV KNOCK SENSOR NOISE

#### SUBJECT: SERVICE MANUAL UPDATE - SECTION 6E - REVISED KNOCK SENSOR NOISE CHANNEL SCAN TOOL INFORMATION

#### MODELS: 1997 BUICK SKYLARK 1997 CHEVROLET CAVALIER, MALIBU 1997 OLDSMOBILE ACHIEVA 1997 PONTIAC GRAND AM, SUNFIRE

1997 CHEVROLET AND GMC S/T MODELS WITH 2.2L AND 2.4L ENGINE (VINS 4, T - RPOS LN2, LD9)

THIS BULLETIN IS BEING ISSUED TO REVISE THE ENGINE DATA 1 SCAN TOOL DATA TABLE FOR THE FOLLOWING SERVICE MANUALS:

* 1997 GMP/97-J-2, PAGES 11 AND 417 * 1997 GMP/97-N-2, PAGE 9 * 1997 GMP/97-L/N-2, PAGE 9 * 1997 GMP/97-S/T-2, PAGE 416

IN THE ENGINE 1 SCAN TOOL DATA TABLE, THE KS NOISE CHANNEL PARAMETER WILL DISPLAY A NUMBER FROM 0-255. THIS PARAMETER IS A ROLLING COUNTER. WHEN ENGINE KNOCK IS PRESENT, THE KS NOISE CHANNEL PARAMETER SHOULD INCREMENT TO 255, RESET TO 0 AND START INCREMENTING AGAIN. IF NO ENGINE KNOCK IS PRESENT, THE KS NOISE CHANNEL PARAMETER DOES NOT INCREMENT.

IN THE ENGINE 1 SCAN TOOL DEFINITIONS, THE RANGE OF THE KS NOISE CHANNEL SHOULD INDICATE THE 0-255 ROLLING COUNTER.

PLEASE MARK UP YOUR SERVICE MANUAL WITH THESE REVISIONS.

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.

COPYRIGHT 1997 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.