For 1990-2009 cars

# MINIMUM IDLE SPEED ADJUSTMENT DON'T USE THROTTLE STOP SCREW

ADJUSTMENT OF IDLE SPEED BY USING THE THROTTLE STOP SCREW (MINIMUM IDLE SPEED ADJUSTMENT) SHOULD NOT BE ATTEMPTED ON THE ABOVE ENGINES. IDLE SPEED ON THESE ENGINES IS ECM CONTROLLED AND CANNOT BE ADJUSTED WITH THE THROTTLE STOP SCREW. IF IDLE SPEED IS INCORRECT, SEE "DRIVEABILITY SYMPTOMS", SECTION 6E2. THE THROTTLE STOP SCREW IS FACTORY SET AND SEALED. ADJUSTMENT MAY BE NECESSARY ONLY WHEN THE THROTTLE BODY HAS BEEN REPLACED.

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.