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

VEHICLES AFFECTED: 1988-90 'B' 5.0 (VIN Y)

This bulletin applies to Section 6E1 "Driveability and Emissions" to 1988, 1989 and 1990 Service Manuals with 5.0L "B" (VIN Y).

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 convenience centre and reminder package (if equipped) or timer module should be disconnected and then note if the fault is resolved. A short in any of the previously mentioned modules or wire common with Circuit 437 can set a Code 24. Refer to the 8A Section, Page 33-0 for more information on this circuit and vehicle speed sensor.

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.