Used Mercedes-Benz GLS Brake Light Switch

Yes, every variant of the Mercedes-Benz GLS has a brake light switch — it is a standard component on all petrol and diesel versions, including AMG models, as it is needed to activate the brake lights and communicate with the gearbox and stability systems. It sits on the brake pedal bracket under the dashboard and is not engine-specific, so all GLS variants across all generations carry one.

The X166 and X167 are distinct generations with different pedal box assemblies, so a brake light switch from the first generation (2016–2019) is unlikely to be a straightforward swap into the second generation (2019 onwards). You should confirm the exact part number against your registration with the breaker before buying, as even where the switch looks similar the connector and thread pitch can differ across that generational boundary.

No, trim level does not affect brake light switch fitment on the Mercedes-Benz GLS — the switch sits on the pedal bracket and is common across SE, AMG Line, and Grand Edition variants within the same generation. Trim only governs cosmetic and interior features, so you can disregard it when searching for this part, though you should still match the generation and confirm the part number with the breaker.

For a brake light switch specifically, engine size does not affect fitment — the switch is mounted on the brake pedal assembly and serves the same function regardless of whether the vehicle is a 350d, 400d, or a petrol AMG 580. Match the generation (X166 or X167) and confirm the part number with the breaker against your registration, and you should be fine.

This is worth approaching carefully, because 2019 sits right on the boundary between the first-generation X166 (2016–2019) and the second-generation X167 (2019 onwards), and production overlap means year alone is not a reliable guide. Confirm the exact generation of both vehicles — ideally by VIN or registration — with the breaker before purchasing, as the two generations are unlikely to share the same switch.

The GL and GLS share the X166 platform, and in some cases the pedal box components are closely related, but connector configurations and software compatibility can vary — so while there is a reasonable chance of similarity, you should confirm the exact part number with the breaker against both registrations rather than assume the two will interchange.