Mercedes-Benz GLS ECU Replacement Parts

Yes, every variant of the GLS has at least one ECU (Engine Control Unit) — it is a fundamental component on all petrol and diesel versions across all generations. The GLS range has covered engines including 3.0-litre six-cylinder diesels, V8 petrol units, and plug-in hybrid powertrains, each with its own specific ECU. Because the ECU is programmed to the engine code and fuel type, you need to know your exact engine code before searching for a used unit.

The GLS nameplate launched in 2016 when Mercedes renamed the GL-Class; the first-generation GLS (X166) ran from 2016 to 2019, and the second-generation GLS (X167) arrived in 2019 and continues to the present day. These two generations use different platform architectures, different engine families, and entirely different ECUs, so a unit from an X166 will not cross over to an X167. Always confirm which generation your vehicle belongs to using your registration or VIN before approaching a breaker.

A 2018 GLS is a first-generation X166 model, while a 2020 GLS is a second-generation X167 — these are entirely different platforms with different engine management systems, so the ECUs are not interchangeable. Even if both cars share a similar engine displacement on paper, the hardware, connectors, and software architecture differ between generations. You need to source an ECU from the same generation as your vehicle and, critically, from a car with the same engine code.

Trim level alone does not determine ECU fitment on the GLS; what matters is the engine code, fuel type, and gearbox type, not whether the car is badged AMG Line or a standard specification. Two GLS models with the same engine code will use the same ECU regardless of trim differences such as alloy wheel design, interior finish, or exterior styling packs. Focus your search on matching the engine code shown on your V5 or confirmed via a VIN check, and supply that code to your breaker.

No — diesel and petrol engines use completely different ECUs that are calibrated for their specific fuel delivery systems, injection timing, and emissions strategies, and they are not interchangeable. Even within the same generation and model year, a diesel GLS ECU will not suit a petrol GLS and vice versa. Always confirm your engine code and fuel type with your breaker so they can source the correct unit.

This is an important question, but whether a specific used ECU will pair successfully with your GLS immobiliser and other control modules is something you need to confirm directly with your breaker and your chosen installer or dealer, rather than take as a given. Mercedes-Benz vehicles typically require the ECU to be coded to the vehicle, which usually involves specialist equipment and may affect whether a used unit can be reused at all. Raise this with the breaker against your specific registration before purchasing, as the practicalities can vary.