For 1990-2009 cars

# 20 AMP BATTERY FUSE REPLACEMENT

GR.8 REPLACEMENT OF 20 AMP ECS BATTERY FUSE DO NOT REPLACE THE 20 AMP ECS BATTERY FUSE WITH THE IGNITION IN THE ON POSITION. IF THE ECM RECEIVES VOLTAGE ON CIRCUIT #480 AFTER ALREADY HAVING RECEIVED VOLTAGE ON CIRCUIT #439, ECM DAMAGE COULD RESULT. THE SYMPTOM WOULD BE EITHER NO ECM "POWER-UP" AT IGNITION ON OR NO ECM "POWER-DOWN" AT IGNITION OFF. IF THE ECM FAILED TO "POWER-DOWN", AN OVERNIGHT BATTERY DRAIN WOULD RESULT.

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.