GM Service Manual Online
For 1990-2009 cars only

PROPER ECC GROUNDING IS NECESSARY FOR ECC OPERATION

ECC GROUNDING MUST BE PROPER FOR ECC FUNCTIONING THE ELECTRONIC CLIMATE CONTROL (ECC) WILL NOT FUNCTION IF IT IS NOT GROUNDED PROPERLY. FOR PROPER GROUNDING, THE GROUND WIRES SHOULD BE CONNECTED BY THE BOLT UNDER THE CARPET JUST RIGHT OF THE LOWER BLOWER VENT ON THE PASSENGER SIDE ILLUSTRATED BELOW.

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.