zitsky

I swear I’m not making this up. I enter the garage get close to something in front but not all the way. Car shuts off for 15 seconds. Then turns back on. It was on COMFORT mode. Haven’t seen it happen in three months of ownership. 15 minutes before I opened the door with engine running and closed it.

SW20S

Sounds like the engine start/stop...

zitsky

Do you mean ECO Mode?

SW20S

No, engine stop/start. Unless you turn it off it will turn the engine off when you're idling and start it back up again when you put your foot on the gas, or when it needs to in order to run the alternator. Have you noticed at red lights that the engine shuts off and comes back on like a hybrid?

zitsky

It was more obvious on the CLS *loaner* I just had. On the S560 I do notice a shudder. I will watch the tachometer on the S class.

seamus2154

I have had that happen parking and pulling in garage if close to a stop. Its the start/ stop.

2012 merc amg

Best off to turn the eco switch off whenever you get in the car and start it, the eco mode start/stop and engine going into 4 cylinder mode is not good for the engine long term.

Tom in Austin

You might not have noticed start/stop before if your battery is below spec. On my car, this function only worked after a long highway trip when the battery reached enough of a charge for the engine to shut off. Since I replaced the big battery a couple months ago, it stops almost every time now. And it restarts much more gently. With the old, weak battery you could feel the engine shake a little as it came back on.

I'm curious how much benefit this really provides, I haven't noticed any thrilling increase in gas mileage.

SW20S

I had mine coded off

C Swenson

Yes, zitsky, ECO mode.

"ECO Start/Stop Technology from Mercedes-Benz works to save fuel and reduce emissions by shutting off your engine when you don't need it."
Or even when you do need it.

seamus2154

Exactly! I had just replaced my aux battery and have been using a battery tender when not in use. Well everytime I get in the car with a full charge the start/ stop is kicking in all the time now! Prior with no battery tender and sitting for a week at a time, battery was never at full capacity or the level for start/ stop. So my good maintenance has bit me in the ***. LOL

Mitch Alsup

Do you know where to get a new battery that does not deliver a full charge--just so that damnable start/stop function stays off............

seamus2154

Unless your a daily driver or just came back from a roadtrip, the battery is almost never fully charged. My S is a second car and can sit from 1-2 weeks and sometimes longer. When I start using it, the start/stop never kicks in. But after highway use and using daily, or a road-trip she gets fully charged and that start/ stop then kicks in at each stop light. This time I know I was leaving it for a month, so I put a battery tender on it. Took it out today---full charge right from the get go, and start stop is working well.....and driving me nuts--- till I hit the button.

Tom in Austin

Your werkshop can do something in xentry to see the charge level and condition of the starting battery. Mine was low and over six years old, so I replaced it just to be on the safe side (might have kept working for another year for all I know).

My start/stop kicks in all the time now since I replaced the battery, including when the car hasn't been driven for a week. I also did my aux battery over the summer as well, and I believe the condition of both batteries is an input to the start/stop.

We're on our third hybrid daily driver, so very accustomed to stop/start from those cars. Honda was especially clever and has a dual A/C compressor that runs on either the belt or an internal electric motor (or both for Max). That keeps the A/C going when the engine shuts down at a light, a darn nice thing on a 100 deg summer afternoon. I think Mercedes' newer 48 volt systems accomplish the same thing by running the water pump and compressor solely on electricity and thus, continuing the A/C when the engine's off.