ECO off memory, stop/start, cylinder deactivation
 

I'm buying a 2019 S560. I don't like two features: the engine stopping when the car comes to a stop, and the engine switching to four cylinder mode when cruising under certain conditions. I doubt that the engineers who designed the cars were fans of either feature. Owners of C7 Corvettes attribute a lot of the car's frequent automatic transmission problems to its cylinder deactivation feature. Is there also a "coasting" feature on the S560? I think that was called "free-wheeling" on some early 50's cars and I thought it unsafe then. I would want all these to be permanently off. Are they all off when the car is in sport mode? I see there is a plug advertised on eBay to cause the car to stay in the last driving mode selected. Does anyone have experience with this device and if so, who made it and what is your experience with it? Will the use of it have any effect on the warranty? Would you recommend resetting it when taking the car in for service? Has it affected any other functions? Finally, for the engineers among us, what happens to the balance of the 8 cylinder engine when it is operating on 4 cylinders? Of course, the same parts are moving in either mode, so in that sense, the balance would not change. But as only 4 of them are firing, would the balance of impulses be more like that of a 4 cylinder engine with massive balancing weights attached to the crankshaft?

Paragraphs make reading easier.

The cylinder disable is quite sophisticated and I doubt you'd even notice it. Most all modern automatic cars use a variation of that "coast" feature these days. I'd bet money your current vehicle does it.

To get rid of stop/start the youtube vid link below works on the SLK`s, you will loose brake hold as a trade off, it has been discussed on three threads on the SLK forum, original poster is COL.
Col found that a faulty sensor stopped cylinder deactivation and stop/start intermittently, he thought at one point that by disconnecting the sensor he would also loose cylinder deactivation as that had happened with the faulty sensor, surprisingly once the faulty sensor was replaced and then disconnected stop/start did not function but cylinder deactivation did, odd that but Col was overly pleased, see post #95 https://www.slkworld.com/slk-r172-ge...ml#post4540864

https://www.slkworld.com/slk-r172-ge...ing-off-5.html

I buy this: https://www.ebay.com/itm/MERCEDES-ca...EAAOSw2iJa-n9S
and it is work on my restyle.
Dealer don`t see these changes and it is no any questions from service. All other function of the car work as at first day (even stuped kicked trunk open - that can not work correctly from the factory).
When you switch on your car - start/stop always off.

Sounds good for 2018/19 cars, unfortunately stop/start was implemented at the end of 2011 (model year 2012) for Mercedes cars as a whole so this device will not work for those cars therefor the only method for cars pre 2018 is the battery sensor disconnect above.
I know brake hold is lost but my experience with my C-Class and SLK is that the auto box holds just fine on hills without any braking. If in the odd occasion the driver feels the necessity to apply a brake there is still the foot or electronic hand brake, to me brake hold is of no consequence compared to ridding myself of stop/start.
With brake hold you still need to have your foot on the brake for safeties sake so I really don`t see the point of it, as said earlier I was not aware of it`s existence for the first 18 months of ownership. Rob.

Cylinder deactivation
 

I currently own a 2018 S560. I have driven back and forth from Florida to RI several times. I could not detect at any time cylinder deactivation. In fact, I was wondering if it really was working. I try to drive as much as I can with distronic activated. I averaged 30 mpg at speeds of 75.
Concerning brake hold, once I activate that feature I never have to keep my foot on the brake. Granted Florida for the most part is flat so I rarely if ever have tried it on a hill.
I’ve gotten use to eco mode with engine turning off at idle. Several of the traffic lights in Florida are quite long so I believe it is actually saving me on gas in the long run.

Quote Concerning brake hold, once I activate that feature I never have to keep my foot on the brake. Quote

For me I always used to keep my foot on the brake just in case the brake hold decided to let go, it is electronic you know and can fail as the car ages.
As with stop/start you either love or hate it, if you hate it the simple method is disconnect he battery sensor.:)

I just turn off the green button and that stops the start/stop. I also thought that the cylinder cutoff only happens in Eco mode.

You can have your car re-codes by BenzNinja to get rid of the start stop. Not sure about cylinder deactivation. I guess if you can’t detect, why worry about it?

Yep, Benz Ninja decoding is the RIGHT way to do it. He did my 2015 S63 Coupe
My start stop only operates if I turn it on. Other things, shut down of the climate control with the fan button, fuel displayed in gallons instead of %, chec out his page, all 5 Stars. Good luck

I have a 2015 S350 Diesel LWB AMG line in UK and I just disabled the stop start using my Launch x431 Pro (£395 off ebay) no problem and I also changed my DVD player to region free, so far I haven't found anything that my scan tool cant do yet?