GM Service Manual Online
For 1990-2009 cars only

EFI DIAGNOSIS REVISION INFORMATION CODE 24

EFI CODE 24 CHARTS. THERE ARE TWO METHODS OF MOUNTING THE VSS - ONE IN THE I.P. CLUSTER AND ONE JUST UNDER THE STEERING COLUMN. THE CARS WITH INTERGRAL VSS REQUIRE REMOVAL OF THE I.P. CLUSTER TO TEST FOR PROPER VOLTAGE. ALSO, THE CHEVROLET DESIGNED ENGINES USE DIFFERENT LOGIC THAN THE PONTIAC DESIGNED, SO FOUR TYPES OF CHARTS ARE REQUIRED.

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.