Some owners of certain GMC Sierra, Sierra HD and Yukon models may have noticed their vehicle’s headlamps and or/turn signals stay on, flicker, or are completely inoperative. While this issue is certainly annoying (and potentially hazardous), the fix could be rather straightforward if the vehicle is also equipped with a factory-installed GM Accessory Illuminated Emblem.
According to GM Techlink, water intrusion from the GM Accessory Illuminated Emblem could cause this shorting/flickering condition. Technicians are instructed to inspect for water intrusion and corrosion at the electrical connection for the illuminated emblem, as well as at the driver-side headlamp connector and the inline accessory harness. If water intrusion or corrosion is found, the technician will perform any necessary repairs to the headlamp connector and clean the headlamp assembly terminals.
Models affected by this problem include the 2020-2022 GMC Sierra 1500 and Sierra HD, as well as the 2021-2022 Yukon and Yukon XL.
To prevent further improper operation, GM technicians will be instructed to bypass the accessory harness by plugging the original headlamp connector from the body harness back into the headlamp assembly. This will temporarily disable the Illuminated Emblem for the time being. GM says it will release a more permanent repair that will allow the Illuniated Emblem to be used once it’s available.
GM says that if there is not any water intrusion or corrosion found at any of the connectors, the GM Accessory Illuminated Emblem is not the source of the shorting/flickering condition. In this case, the automaker advises technicians to follow normal system diagnostics procedures, although the wiring harness for the Illuminated Emblem “should still be disabled to prevent any improper operation in the future.”
The GMC Accessory Illuminated Emblem is available in both Red and Black finishes and is compatible with the GMC Sierra, Sierra HD and Yukon.