Used Mercedes S-Class Coupé 2014-2020 reliability

The S-Class Coupé is a large car, so check the bodywork carefully for any scuffs or dents – these can be expensive to set right. Also make sure that all that electrical equipment on board works as it should, including the seats, infotainment system and boot lid.

Reported problems with the S-Class Coupé are relatively few, and on the whole owners seem happy. Most problems seem to centre on non-engine electrics, which is why it’s always good to check these carefully.

Automatic gearbox malfunction

This applies to diesel models. The wiring harness that controls the gearbox can be damaged by the hot exhaust, and this can make the car go into neutral while driving. The harness should be inspected and either replaced or simply rerouted.

Rear seatbelt malfunction

The seatbelt extender in the back seat might not retract correctly when in use. If the pretensioners in the system deploy in a collision, there’s a risk that parts from it could work loose and cause injury to occupants.

Engine might not restart

Due to an issue in the wiring harness that sent a faulty camshaft signal that confused the engine start/stop system and caused it to cut out altogether, you might have to put the car in park and restart it manually when you've come to a stop.

Airbag might not perform correctly

Some front passenger airbags weren’t installed correctly. Parts of it could therefore detach when the bag goes off and cause injury to occupants. As part of the recall, Mercedes will fit a new airbag module if required.

Reliability has been a little mixed of late, and the S-Class didn’t feature in our most recent survey. However, the latest E-Class and the C-Class all did well in their respective groups, finishing 12th and 8th respectively, although the brand as a whole finished in 24th place out of 32 manufacturers.