Deezwho

Yesterday I drove my 2021 G550 but I forgot to put it in Sport mode for the first time.
while I was driving, every time I stopped at a red light, a yellow A with a slash through it appeared on the dash and the engine stayed on the whole time.
Is there something else that keeps the engine from turning off when idling? Or is it not working for some other reason?
Not that I’m complaining since I hate that “feature” but wanted to understand why it was doing that

Hodog16

My guess is either you didn't push hard enough on the brake to activate it (seems like most systems are programmed not to activate if the brake pedal is only lightly pushed) or you were running heavy air conditioning which was power intensive so that the system didn't want to engage.

3.Pointed.Czar

lol good. Despise the feature with every fibre of my being. The gas it saves you is negligible unless its true stop for 10 mins and go traffic. Not to mention the unnecessary wear and tear of components to constantly stop and start your engine and Ive talked to Mercedes, Subaru and Toyota techs that all verify this.
With my old beamer it was possible to get it coded out completely by pressing the off button once and it was done at a BMW dealership. Now when I asked the Mercedes shop they say they wont do it and are not allowed.
First button I press when I start the car is to turn the damn thing off.

streborx

Did you accidentally press the "A" button adjacent to the ignition start button when you started the vehicle? This button is supposed to shut the ECO Start/Stop function off, just like shifting into sport mode, but this button has never functioned on my '19 G550, so I'm just guessing here.

streborx

MB is probably telling you the truth about not being allowed to disable it. My understanding is MB scores extra EPA mileage points for making the vehicle start with this function defaulted on. The easiest way to permanently disable it is to disconnect the connector on the sensor that's mounted on the main battery negative terminal. Alternately, you can purchase the OBD dongle (~$150) from Mid-City Engineering, which allows you disable/enable it as you wish. I yanked my battery sensor cable more than a year ago and I've never had any problem or experienced any error codes.

Deezwho

I live in Orlando so the AC is always on and set to a low temp plus I set it on recycle every time I start the car for extra cooling power. I’ll try turning off the AC next time I go out and see if it activates the feature.
I guess it’s another benefit of living in Florida beside no income tax lol.

The feature is definitely “on” because if I push the A button when the yellow A slash light comes on it changes to “A off”

Hodog16

Yup I miss those no state income tax years. I used to live in Jacksonville.

Also try to push harder on the brake pedal. My guess is it’ll engage then.

streborx

I don't think the AC regulates the ECO Start/Stop, but the oposite is true. When the engine shuts off at a stop light the AC compressor stops. You might not notice during a brief stop, but after a couple minutes, the blower will slow down and the air coming out of the vents gets warm. This is probably the best reason to disable it, especially in warm humid climates.

084runnerltd

There are a few things that can effect it, but it basically comes down to the battery’s charge level. (I believe the manual outlines the parameters for when the stop-start system is automatically disengaged.)

Last winter when starting my G after it sat in a cold parking lot all day, the auto-start stop was disabled for a few minutes.

It is normal, however, if you are frequently having this happen and you don’t log many miles (aka: allow the battery to charge) you might want to throw a trickle charger on it or take it for a longer trip to get it all charged up.

streborx

Engine temp and battery charge status are two main inputs to the ECO Start/Stop status, but my understanding is that there are others. I dislike unknown factors deciding when to shutdown the engine, and the expectation that I'm supposed to be monitoring the instrument panel at all times for presence of a lit icon so that I can adjust my driving style. I've seen several YouTube videos by professional mechanics railing about the excessive wear and tear on starter motors and batteries as a result of ECO Start/Stop, but I have yet to see Greta Thunberg praise how it's saving planet Earth from climate destruction. I'm satisfied that it's easy to permanently disable.

300SE1993

Sometimes when I forget to disable it manually with the button, I notice that when the engine is cold, I see the yellow symbol you mention. I just figured it was because the engine is cold.

084runnerltd

The best resolution to this issue:

https://www.midcityengineering.com/p...s-benz-ecopcm/

juanmor40

If I understood (another thread) correctly, within the XEntry MB tool, the ECO Start/Stop "feature" has 3 options: Always ON (current default), Always OFF, and LastSetting.

If you have an independent willing to code it for you, you can have it whichever way you want it and done with it. Dealers will not code it for you as far as I have heard.

When I install my XEntry tool, I will modify it to LastSetting (or whatever the name is in the program) so I can turn it on/off at will

084runnerltd

You could be correct on that, I am not sure when it comes to coding

On the product below, it remembers the last setting. Which for me is “off” 100% of the time. 👍🏼

https://www.midcityengineering.com/p...s-benz-ecopcm/

WillinMA

I'm working with them also on their other product that defaults the driving mode - but it actually doesn't work on the W463A models right now and they have some modifications to do to enable it. If you can get it to switch to individual mode at startup, you would just program the Start/Stop to off in that dynamic mode (plus all the other options like shocks, transmission, etc). I also have the RennTech ECU on my G550 and had asked them to code out the eco start/stop as part of the ECU software load.

https://www.midcityengineering.com/product/eco213/

Surge

Back to the OP’s question - when it’s in yellow, it’s been disabled or there’s a problem with the system. The symbol and colors vary by market.
There is no display if the system is active but has not shut down the engine, so that’s not what it is.
Push the start/stop enable/disable button to see if you can make the yellow icon disappear.

FWIW, I have asked a good friend who is the head AMG mechanic at my dealership and there is no evidence that starter motors need to be replaced more often with auto start/stop enabled. But it does stand to reason that the motor will fail faster, but by that point the fuel savings will have likely outweighed the cost of the starter motor.

Deezwho

Yea it must have been either engine cold or (relatively) low battery condition as most of my driving is less than 5 miles. Wife drove the car about 20 miles the other day and she said the auto start stop activated toward the tail end of the drive.
Now it's back to Turn on Car, engage Sport mode, and not worry about it until the next drive lol

streborx

The ECO Start/Stop feature is why the G hauls around an H8 size battery that's nearly double the size and weight of conventional batteries. It has 2 integral fold down handles for lifting its 60 lb (27kg) mass. No need to add sandbags to improve winter traction.

fabbrisd1

I guess some people need friendly chatter.

Since Forum members are computer savvy - please take the Opportunity to Download a Searchable Pdf copy of your Own Owners Manual : CLICK HERE DOWNLOAD PDF OWNERS MANUAL

1. Yellow = Pg 132/or about - is ENTIRELY CLEAR - "not all conditions for an engine stop have been met" and still the chatter goes on.

2. Sh*t - if Eco Start/Stop bothers you - at all - then Buy-The-Dang-OBD-Module - Mid-City or canfiltermb@gmail.com. The "last setting" programming is slick - OBD plugs in once, and 15 secs you are done, and the module comes out. Keep the module in case you ever want to go back to original factory settings. This re-programming does not void MB-warranty in any way-shape-form.

3. NO - Eco Start-Stop is NOT any kind of Dis-Stress for European engine components - and any "Tech" who says different is smoking crack.

4. Eco Start-Stop came about from EU Mandate for ALL New Cars there starting 5-6yrs ago - Euro mandated 3yrs ago that it not be Programmable-For-Permanent-Delete - Eco Start-Stop has ZERO to do with US Standards in any way-shape-form.

3. No - Renntech will NOT be adding Eco Start/Stop to their HHT programming. I am a HUGE fan of Renntech HHT, any G63 owner that DOESN''T have HHT is missing a Huge Thrill.
RennTech is the Top Tuner because their tune(s) work within factory emission control system (no check engine lights) - that's has always set RennTech apart from the "hack-a-tunes" - and NO Renntech is not going
to mess with ECO Start-Stop

Deezwho

"not all conditions for an engine stop have been met" is anything but "entirely" clear.
What conditions have not been met? I did not see a breakdown in the owners manual stating what all the conditions are that are required for the activation of start stop unless I missed it? Shouldn't the owners manual specify the exact conditions required to activate a feature integral to the basic operation of the vehicle?

300SE1993

Before I even read who posted this, I knew who it was. Nobody else on this entire forum is so rude and condescending.

Surge

It’s not in the manual! I also checked, and on page 134 (being more specific than “132/or about”, and there is zero mention of the amber start stop light.
If you go to the trouble of posting this, why not actually read the section you’re quoting!?

Not sure what Renntech has to do with this thread?

streborx

As I have opined in numerous other threads, the G's owner's manual is useless, filled with errors, inaccuracies, and omissions, lacking fundamental information essential to a car's owner/operator. It does not even reveal the location of the battery, but instead advises you to go to the dealership if you encounter a battery problem (duh!). MB knows that nobody ever RTFMs, and consequently invests no effort to produce anything worth referencing.
My favorite entry is in the index where it states "Fuses - See Fuses".

juanmor40

( I do not own a G Class, but I just downloaded the MY21 G Class manual, and definitely, it is not that good )
. Soon, the owner's manual would be by appointment only at the stealership. So, they close the documentation department and charge us for answering anything.

streborx

Responding to your points individually (and with all due respect to you):

1. I have never observed a yellow light on my instrument cluster, but this might be a consequence of the yellow light being specific to MY2020+ vehicles and/or specific to the analog instrument cluster. My digital instrument cluster exhibits a white-on-black "A" with the circumscribed circular arrow, either at the bottom-right or top-center (depending on the digital instrument cluster design selected). This "A" icon appears whenever the ECO Start/Stop function should activate, but does not, such as those mystery conditions that keep the engine running when the vehicle has been braked to a full stop for at least 1 second. As I've also previously mentioned the "A" button next to the ignition start/stop button on my G has never produced any enable/disable result, so its purpose is a mystery (despite what the owner's manual indicates).

2. As I have posted earlier here and on other threads the Mid-City and Vladimir-of-Belarus OBD dongles are solutions that retain the the dynamic mode setting, thus disabling the ECO Start/Stop when you shut off the engine while in Sport or Sport+ modes. I just simply disconnected the battery current sensor so that the ECO Start/Stop system thinks the battery charge state is insufficient to support starting the engine. This results in the "A" icon's presence on the instrument cluster, but throws no other OBD codes or instrument cluster warnings (and keeps ECO Start/Stop disabled permanently in all dynamic modes).

3. ECO Start/Stop is more stressful to the vehicle, hence the monster battery that I described in an earlier post. Hopefully, the engine's starter and associated electrics have been beefed up to handle the many additional engine starts that occur with this enhanced fuel saving system. Perhaps one of the ECUs accumulates a tally of ECO Start/Stops that the vehicle experiences, such that if the starter needs replacing at 100K miles, it can be determined that the starter was used 739,643 times, and that's why its bearing are shot. I've read elsewhere that the period during which the greatest engine wear occurs is during the first 30 seconds after the engine is started as this is the time during which oil is first pumped through the engine to lubricate it, but I have no personal experience on which I can substantiate this. But starting and stopping the engine 30 times on the way to work and 30 more times on the way home doesn't sound like a good idea to me, even if it does save a cup a gasoline each day.

4. ECO Start/Stop may well be an EU mandate, but here in the U.S. it seems not to be mandatory. A friend of mine purchased a GM pickup truck with this feature, and the dealer disabled it permanently upon his complaint and request. MB dealers will not do this, and the superficial research I've done on the topic reveals that the EPA awards bonus mileage points if the manufacturer configures the vehicle to always start with ECO Start/Stop enabled. If MB took advantage of the bonus points, they are probably prohibited from disabling this feature. However a vehicle's owner can choose to do as he/she pleases with an OBD dongle. There is legal controversy, however, as to whether this constitutes tampering with the vehicle's emissions system which is illegal. IMHO adding an OBD dongle that merely automates what can be accomplished by pushing the Dynamic mode switch into Sport mode isn't committing a crime.

5. I inquired with Renntech shortly after acquiring my G and asked if its tuner disabled ECO Start/Stop, and was disappointed to learn that it doesn't. That alone would have prompted me to cough up $2400, and the extra 107 ponies would have been a free bonus. Having solved the annoyance of ECO Start/Stop, I've still considered the Renntech upgrade, but don't think I'd appreciate (or much ever get a chance to use) the extra HP. There just aren't that many places (even here in rural Colorado) where I can "let 'er rip". And honestly, a G Wagon is the last vehicle I'd take to a track to see what 500+ HP could do. If the G Wagon is reincarnated with an IL6 turbo, with only 350 HP, I'd still buy one (although I might reconsider the Renntech).