2004 GMC Yukon

On certain vehicles, the interface between the electrical terminals of the Heating, Ventilation, and Air Conditioning (HVAC) blower relay resistor module and the wiring connector (which powers the module) may be incapable of conducting higher current levels for sustained periods of operation. In addition, moisture and other contaminants (such as road de-icing materials) may enter the fresh air intake plenum and contact the internal circuit of the module or corrode the terminals. These conditions may cause the relay resistor module or wiring connector to overheat, causing various symptoms such as: the HVAC blower may not function on certain or all blower speed settings; a burning-plastic smell or smoke may be present in the vehicle, or; the HVAC blower may run continually with the ignition in the OFF position. These warning signs could, in certain instances, be leading indicators of an impending vehicle fire, which could result in property damage and/or personal injury. Correction: Owners will be provided with additional warranty coverage for the blower motor resistor module/wiring connector overheating condition. Under this "special warranty coverage", should this condition occur within 10 years or 240,000 km from first vehicle registration, dealers will install a replacement blower motor resistor and resistor module connector.

On certain vehicles, the relief valve o-ring seal within the brake hydro-boost module could fail. If this happens during braking applications, the driver may be able to hear an engine compartment noise similar to the sound that occurs when the steering wheel is turned to a full stop position. The driver could also experience a slight increase in steering efforts while braking and parking. Under certain driving conditions, a slight increase in the applied brake pedal effort may be required to achieve the same vehicle deceleration rate as prior to the seal failure. Correction: Dealers will inspect the hydro-boost module, and replace it, if necessary.