For 1990-2009 cars

# INFO ON SPEEDOMETER MOVING WHEN IN PARK OR NEUTRAL

THIS IS A MONTHLY SERVICE NEWSLETTER ARTICLE. THIS BULLETIN IS NOT INTENDED FOR PUBLICATION.

#### SUBJECT: INFORMATION ON SPEEDOMETER MOVING WHEN IN PARK OR NEUTRAL

#### MODELS: 1997-1998 BUICK C, G, W BODY WITH 3800 SUPERCHARGED L67

THE SPEEDOMETER OR HEAD UP DISPLAY (HUD) MAY INDICATE A MPH OR KM/H VALUE OTHER THAN ZERO WHEN THE VEHICLE IS NOT MOVING. A SIMILAR CONDITION MAY SHOW ON A SCAN TOOL.

THIS IS CAUSED BY ELECTROMAGNETIC INTERFERENCE (EMI) INDUCED INTO VSS WIRES FROM THE FUEL INJECTOR WIRING.

TO REDUCE THE INDICATED SPEEDOMETER OR HUD VALUE, SEPARATE THE VSS WIRES FROM THE WIRING HARNESS BUNDLE NEAR THE PCM. UNTAPE THE PCM WIRING BACK ABOUT 12 INCHES FROM THE PCM. LOCATE THE VSS WIRES (YELLOW AND PURPLE WIRES) AND LOOSEN THEM UP IN THE WIRE BUNDLE AND RECHECK THE CONDITION. REPOSITION THE VSS WIRES AGAIN IF NECESSARY. LOOSELY RETAPE THE WIRING BUNDLE AFTERWARDS.

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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.

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