INFORMATION ON TACHOMETER ACCURACY. GMC Truck GMC Suburban

SUBJECT: INFORMATION ON TACHOMETER ACCURACY

MODELS: 1992-94 CHEVROLET AND GMC C/K TRUCKS WITH A TACHOMETER (RPO U16)

THE TACHOMETER USED IN C/K TRUCKS WITH RPO U16 IS CALIBRATED SO THAT THE FIRST MARK SHOWN ON THE TACHOMETER DISPLAY IS 500 RPM. AT IDLE, THIS MAY LEAVE THE IMPRESSION THAT ENGINE SPEED IS TOO LOW OR THAT THE TACHOMETER IS INACCURATE WHEN NEITHER IS THE CASE.

IF ENGINE IDLE SPEED IS NORMAL AND THE TACHOMETER APPEARS TO BE CORRECT AT ENGINE SPEEDS ABOVE IDLE, THE TACHOMETER IS OPERATING AS DESIGNED AND NO ATTEMPT SHOULD BE MADE TO ALTER THE VEHICLE TACHOMETER READING AT IDLE.

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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.