I recently bought a used E300 Hybrid (W212) from 2014 from an official Mercedes dealer. The car is awesome and great fun to drive but the hybrid features have only worked for a few days right after I bought it and have not worked since. By "hybrid features" I mean the engine turning off when you lift and coast or when stopped at a red light. Also, the car used to start silently without turning the internal combustion engine on in the few days that the "hybrid features" worked but now it almost immediately turns on the engine as soon as I turn the key. The READY indication on the dashboard is always green and I've never seen a warning light come on or indication on the dash that something may be wrong with the car. Strangely, the car does charge the battery when I lift and coast (the charge needle goes positive; down) and injects electric energy into the drive whenever I hit the gas pedal aggressively enough (the charge needle goes negative; up).

So what gives? Why isn't the car turning the combustion engine off and switching to battery power when stopped at red lights, crawling through traffic at less than 50kph (as stated in the manual) or coasting on the highway? Is this some sort of protective feature that kicks in during February or something? Temperatures haven't been too low where I'm at and have oscillated between 7C/44F and 16C/61F, though relative humidity has been high due to very close proximity to the ocean (1 minute away).

Have dealer check it, for bulletins & service campaigns search “hybrid” here: https://mbworld.org/forums/e-class-w...212-sedan.html

Not sure how MB hybrid system works exactly, but most system will start the ICE to get it warmed to regular operating temperature. So in cold weather is may run longer for that purpose or to provide heat for climate system. Another factor is the SOC of the hybrid battery.

Thanks for the replies, guys!

Hmm, what does SOC mean?

State of charge.