A humming or buzzing sound may be heard coming from the front of some 2025 Tahoe, Suburban, Yukon and Escalade models. (Fig. 4) The sound may be the headlamp mounting amplifying the normal resonance of the headlamp cooling fan.
Fig. 4
The headlamp cooling fan directs airflow over the components to help dissipate heat, enabling the LED bulbs to operate at optimal temperature levels. Direct contact between the headlamp assembly and the vehicle body may lead to increased vibration and noise transmission.
To determine if the internal cooling fan is the source of the noise, check the headlamp assembly with the headlamp switch on and off. Cycle the headlamps on and off while monitoring for changes in the humming/buzzing sound. Loosen the headlamp and reposition it to observe any change in noise or vibration.
If the headlamp assembly is confirmed as the root cause, apply 1-inch squares of foil-backed butyl tape to the headlamp mounting locations. (Fig. 5, Tahoe shown)
Fig. 5
The foil-backed butyl tape (Fig. 6) will dampen vibration and eliminate resonance transfer to the surrounding body panels.
Fig. 6
Refer to Bulletin #25-NA-250 for additional information, including part numbers.
– Thanks to Rich Renshaw
