The GM TSB document sent to dealerships says that “certain 2021 model-year Chevrolet Suburban and Tahoe vehicles may have a condition in which the daytime running lamps may shift to a bluer shade of white in its lit appearance. The document also indicates that this bluer light color will “remain in effect until the headlamp cools.”
In order to remedy this problem, Chevy dealerships have been instructed to replace both the front left and front right LED driver module assemblies. These repairs will take about one hour for a certified GM service department to complete. This fix requires one replacement part to fix, the “Module ASM – Headlamp LED Driver” (Part No. 84551653) although two of these parts are required for either front DRL.
GM says that all vehicles affected by this problem that are in dealer inventory “must be held and not delivered to customers, dealer traded, or used for demonstration purposes until the repair contained in this bulletin has been performed on the vehicle.” It’s not clear how many vehicles are affected by the issue. A decent number of 2021 Chevy Tahoe and Chevy Suburban models will still be on dealership lots, as the full-size SUVs only began rolling off the line at the GM Arlington Assembly plant in Texas relatively recently.
The 2021 Chevy Tahoe and Suburban represent the next-generation of the long-running Chevy SUVs as ride on a new T1 platform with independent rear suspension. A naturally aspirated 5.3L V8 L84 gas engine comes standard in the SUVs, which is paired with a GM 10-speed automatic transmission and standard rear-wheel drive or available four-wheel drive.