For 1990-2009 cars

# ELC DIAGNOSTIC REVISION AVOID FALSE INDICATION

1981 ELC DIAGNOSTIC REVISION IN FIGURE 3D-27 TITLED "ELC DIAGNOSTIC CHART - PROCEDURE 1-2", ON PAGE 3D-21 OF THE 1981 SERVICE MANUAL, THE STEP ILLUSTRATED AT THE TOP OF PAGE 2 SHOULD HAVE THE FOLLOWING NOTE ADDED TO IT, IN ORDER TO AVOID A POSSIBLE MISLEADING DIAGNOSIS: ON DFI ENGINES, THE IGNITION SWITCH MUST BE ON WITH ENGINE RUNNING. THIS APPLIES TO THIS STEP ONLY. FOR ANY OTHER TESTS, ENGINE MUST BE STOPPED, AND SWITCH OFF BEFORE THE HARNESS CONNECTION IS RESTORED.

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.