[Gazbo55]

Start stop issues

Hi Guys.
Newby to GLC but not to mercs. Only had my GLC a few days (love it) but as yet not got the eco stop/start to work. My wife owns an E220d rag top and the stop/start works perfectly as it should so concerns are creeping in already. Also the Mercedes me seems to be about as much use as an ashtray on a motorbike. Registered it and was told I had to drive for 15 minuets to activate it but two hours later there's nothing, any advise would be more than welcome.

 

[Ironman]

Same happened to mine when only 1 year old, mentioned to garage and they replaced the battery for free as still under warranty. It's working as before now

 

[Gazbo55]

Just been out and thought I was going to have to eat humble pie when finally it went green but it only lasted about 30 seconds before going back to yellow.

 

[AndrewB]

Mine has'nt worked since I had the first service last November and as most studies say there is litle if any benefit and potential downside in incresed wear and tear and as I always turned it off anyway I wasn't bothered ,but we were parked down by the beach the other day , after about an hour or so a warning message came up to start the engine as the battery was low. I called assistance and they sent a tech round who checked everything ,said the battery was fine and couldn't find any faults on his laptop , suggested too many short trips was why the stop start didn't work . I put the battery on charge overnight still no stop start , I always wanted to turn it off permanently so I guess my wish has been granted , but I'm still puzzled by the low battery warning.

 

[Citizen613]

, but I'm still puzzled by the low battery warning.

I am guessing your vehicle is only a little over 1 year old.

Unless there are other circumstances, say ….time periods with ignition on but motor not running, lights on, many short trips with engine restarts.....and so on ...or pretty much "not normal driving behaviour"
...then in my estimation a low battery warning, while possible ...does sound unlikely.

Which leads to the thinking that there may be some other cause.

I have seen other posts, maybe here or other forums, where folk have had issues with the stop/start function ...and in some cases it was tracked down to some 'earth lead' being faulty. My interpretation is that this faulty lead, provides lower battery voltage readings to the sensors, this in turn negates the stop/start function most of the time and /or prompts a premature "low battery Warning". A replacement battery, may appear to fix the issue, however it just masks the underlying cause until the battery fades a little in its natural life cycle. (i.e. another 12 months)

Get you dealer to check out this possibility. They "should" be aware of it!!!

 

[MAXOU]

After


Vehicle side requirements for automatic engine stop and start
In some countries and regardless of the display on the multimedia system screen, the Start / Stop ECO function is not available in any driving program, due to the quality of the fuel.

Requirements for automatic engine shutdown:
The Start / Stop ECO function is activated.
The outside temperature and the atmospheric pressure are in a range adapted to the system.
The engine has reached its operating temperature.
No motor diagnosis is active.
The engine speed is within a range appropriate for the system.
The box oil temperature is within a range suitable for the system.
The temperature of the passenger compartment is within the set range.
The fuel tank is sufficiently filled.
The system does not detect fogging on the windshield while the air conditioner is running.
The state of charge and the voltage of the battery are sufficient.
The battery temperature is within a range appropriate for the system.
The engine hood is closed.
The DSR is not enabled.
The AIR BODY CONTROL suspension is not raising the level.
Requirements for automatic engine start:
The vehicle starts to move.
The braking system requires the engine to run.
The temperature of the passenger compartment is outside the set range.
The system detects fog on the windshield while the air conditioner is running.
The state of charge of the battery is too low.
Related topics
How the ECO Start / Stop function works
Disabling and enabling the ECO Start / Stop function

 

[dezzertguy]

I have a 2017 GLC43. The start/stop function stopped working last fall and I took it to the dealer this year. They replaced both the regular and aux battery. All under warranty. It is working again.

 

[david.w.faulkner15]

mine was yellow pretty much all the time - even after a 60 mile run.........dealer replaced a "battery current sensor" or something and also allegedly the second battery although on mine I believe it has the capacitor under the floor so not quite sure about that....either way it now, finally appears to be working as it should

 

[david.w.faulkner15]

...looks to me like they've fitted a new starter battery - on a car that's barely over a year old....

 

[luciue12]

My stop/start has not worked since the last software recall was carried out in April 2019. A software recall in August 2018 increased my fuel consumption from 47.8 mpg to 45mpg and then the recall in April 2019 reduce it still further to 42 mpg and also increased my Addblue consumption. The software recalls were supposed to be for emissions improvement, but how can this be when I am now burning more fuel? MB customer facing people are programmed to use clichés and sound bites to fob you off. The obvious answer is don't buy MB and get an Audi.

 

[stubax]

What makes you think Audi are any better?

 

[Urbanpixels]

I have this problem. Mercedes said the battery wasn't sufficiently charged and i should charge it up.

I charged it up that evening and took it for a long drive. Nothing changed. Still just an orange status light on the dashboard

 

[Rush yyz]

Anyone notice their start stop function stay in yellow most of the time?

some day I driven the car all day and the light (on the dash board) still stay on yellow ( which start stop not work)

and some day the light turn green (start stop working) after a 5 mins run..

Really dont know what condition it required for the start stop to be working.

This should shed some light on the mysterious stop/start function. We bought a 2019 GLC 300 we thought the stop start wasn't functioning correct. We took it to the dealer, battery was good everything was operating correct . They added a new software. When we left it worked twice then stop working. I stayed thinking about the problem. I decided that the AC was the only variable that could prevent the function from operating. I noticed that my wife was setting her AC on here side to low 60s. Since we live in Miami setting the AC that low will prevent the stop start from engaging because the engine needs to cool the inside to the AC setting. I decided to set the AC to 77 degree on both side , sure enough the engine turn off when we came to a complete stop. Then we lowered to 75 and it continue to work. So the stop/start function will work considering everything is working good based on your outside temperature and your AC setting temperature. So I suggest try different temperature setting until stop/start engages depending where you live.

 

[Urbanpixels]

Just to update this thread. My Start stop is now working!!

Merc finally recognised the battery as faulty and replaced it under warranty (2017) GLC and the warranty expires next month.

 

[KSS1977]

I too had this, in my case it was because during lockdown the car was sitting about for extended periods. Cars that use AGM batteries go into a low power mode after a while, my BMW Touring occasionally pops up with ' not all electrical functions availbale due to battery' but has also complained about ' charge battery' but thats another story.

I few weeks back I put the GLC onto battery tender for the day, it did take 12 hours to get the car to it's optimum ( much like the overnight charge) at the dealers as described above. After this, green Stop / Start was resumed.

Side note - I hate start stop technology and turn it off when I drive it, but it was annoying me it wasn't at it's optimum.

Anyone reading this that wants to keep their car charged up I consider it good practice to do before the cold snap. Get yourself one of these and leave it connected from the jumper point in the engine bay and earth point on the suspension turret overnight - job done.

 

[johngwallace]

Mine has'nt worked since I had the first service last November and as most studies say there is litle if any benefit and potential downside in incresed wear and tear and as I always turned it off anyway I wasn't bothered ,but we were parked down by the beach the other day , after about an hour or so a warning message came up to start the engine as the battery was low. I called assistance and they sent a tech round who checked everything ,said the battery was fine and couldn't find any faults on his laptop , suggested too many short trips was why the stop start didn't work . I put the battery on charge overnight still no stop start , I always wanted to turn it off permanently so I guess my wish has been granted , but I'm still puzzled by the low battery warning.

Still the same for me, 4 yr old GLC, never worked, car just serviced too, worked after a long run (200km+) on motorway for 5 mins then gone again. Any fixes not involving returing to Dealer Service, usually an expensivw trip !

 

[Demi D]

Just had a new battery, as my stop/start has not worked since I had the car. It worked straight away! But 15 mins later, had the yellow line through, saying not working. So I have no idea what the problem is!!

 

[stamir]

Check your battery. I wouldn't be surprised you need a new one. Alternator is a remote possibility but most likely the battery got old

 

[Jmartens]

I just bought a 2018 GLC, my first Mercedes. I hate start/stop and try to remember to disable it when I first leave in the car. The other day, I forgot to do that...and then realized that the start/stop wasn't working! The light on the button was green though.

Even though I don't like it, I want my car to work as intended and be in good order. Do I simply need a new car batter? Is that covered under warranty (6 months left on factory, then 12 more months of CPO).

 

[Tony Mac]

Same problem on our 2016 250d. Start / Stop hasn’t worked for 2 years - lived with it. But now displaying error Auxiliary Battery Malfunction.

I think the Start / Stop functionality is powered by the Auxiliary Battery - which a Capacitor and not a real battery. This component lives under the passenger footwell and Forum Member TooBad has a thread on this Forum documenting how to replace it.

Not sure whether it’s covered under Warranty?

Be very interested to learn how you get on with this.

Tony