Used Mercedes-Benz CLA Body Control Module

Yes, the Mercedes-Benz CLA is fitted with a Body Control Module (BCM), sometimes referred to in Mercedes documentation as the Signal Acquisition and Actuation Module (SAM) — in fact the CLA typically uses separate front and rear SAM units rather than a single combined BCM, and these handle functions like lighting, wipers, and central locking. When searching for this part, you may need to specify whether you need the front SAM or rear SAM unit. Confirm with the breaker which unit your vehicle requires and quote your registration so they can identify the correct part.

The Mercedes-Benz CLA ran in its first generation (C117) from 2013 through to 2019, with a facelift introduced in 2016, so a 2014 car is pre-facelift and a 2017 car is post-facelift — this is a significant boundary and the SAM unit may differ between the two. Even within a generation, Mercedes SAM units are typically coded to the vehicle and may require programming to your specific car. Confirm with the breaker whether the unit from a 2014 car is compatible with your 2017 registration before purchasing.

The second-generation CLA (C118) launched in 2019 is a substantially different vehicle from the first-generation C117, with updated electronics architecture, so the SAM units are very unlikely to be interchangeable between generations. These parts are also vehicle-coded and will need programming regardless of which generation they come from. Always confirm fitment with the breaker against your exact registration.

Trim level — such as Sport, AMG Line, or Urban — does not fundamentally determine SAM unit compatibility on the CLA, but the specification of your car does matter, as vehicles with different optional equipment (adaptive lighting, advanced security systems, or parking sensors) may use differently configured SAM units. The engine variant (200, 220d, 250, 45 AMG) may also influence which unit is fitted due to differences in engine management integration. Give the breaker your full registration so they can match the correct unit to your car's specific build.

Yes — Mercedes SAM units are coded to the vehicle they were originally fitted to, so a used unit from a breaker will almost certainly require programming or coding to your car before it will function correctly. This is typically carried out using Mercedes XENTRY diagnostic equipment or a compatible aftermarket equivalent. Factor in the cost of programming when budgeting for this repair, and discuss it with both the breaker and your chosen workshop before buying.

The CLA (C117 and C118) shares platform architecture with the A-Class (W176/W177) and B-Class, and some electronic components are shared across these models, so there is a possibility that SAM units may interchange in some cases. However, exact compatibility depends on the build date, specification, and software version of each vehicle, and this is not something that can be confirmed without checking both registrations. Route this question directly to the breaker and provide both vehicle registrations so they can verify whether the unit is a match.