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For 1990-2009 cars only

SERVICE MANUAL UPDATE-SEC.6E1 COMPONENTS SETTING A CODE 24

MODELS AFFECTED: 1988 - 90 ESTATE WAGONS

This bulletin applies to Section 6E1 "Driveability And Emissions" of 1988, 1989 and 1990 Buick Estate Wagon Service Manuals.

This bulletin serves to improve diagnosing Code 24 (Vehicle Speed Sensor). If a Code 24 problem is still present after completion of the trouble code chart, then the following Diagnostic Aid should be checked. The timer module should be disconnected and then note if the fault is resolved. A short in the previously mentioned module or wires common with Circuit 437 can set a Code 24. Refer to Section 8A, Page 33-0 for more information on this circuit and vehicle speed sensor.

Please update your Service Manuals accordingly.

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.