Mercedes-Benz CLC-Class OBD port location

Illustration — use it to know where to look.

Location

RHD (UK): driver's footwell, under the lower edge of the dashboard on the right-hand side of the steering column, above the pedals and immediately alongside the bonnet-release lever — the bonnet release sits on the driver's side on a UK car, so find that first and the socket is right there. Sit in the seat, drop your head to about knee height and look up and outboard. LHD: mirror image, under the lower dash on the left of the column, again above the pedals and beside the bonnet release. Same position on every CLC trim, petrol and diesel, and unchanged from the earlier 203 Sports Coupé — the 2008 facelift reworked the nose, lights and interior trim but did not move the socket. If you have worked on a W203 saloon you already know where this is.

How to access

There is a small plastic flap over it, roughly matchbox size, not an open socket. It hinges down and comes away by hand — get a fingernail under the lower edge and pull it towards you. No screwdriver or trim tool, and these flaps snap if you lever them, so take the fingernail route. The 16-pin connector is visible immediately behind it. On a high-mileage car the flap is often already missing. If the socket is dead with no power on pin 16, the diagnostic connector on the 203 shares a small 5 A fuse with the lighting control module and the brake light switch — check the fuse label in the car's own box before assuming an EIS fault.