W221 S350 not starting (doesn’t even try) after service.

[DSK]

I had a service and brakes job done at MB Centre in Nottingham on 17/11/2023.

On the way home the infotainment thing had a mind of its own. The dash was also displaying traction/stability signs inoperative see owners manual. Switched off the car and on again after some 30 minutes and the stability/traction stuff went away but the infotainment was still doing what it wanted.

This morning, 18/11/2023 I go the car, everything looks ok, lights are strong, key in, the stability/traction see owners manual is present again with the ignition, but, when turning the key further to start… nothing! The engine doesn’t even try turn/start! I tried locking and unlocking etc again but nothing.

MB centre Nottingham are unhelpful and advise having the car recovered to them. Update, they have called to say they will get someone out on Monday and it’s very bizarre indeed.

History, the battery is perfect and the car always on the button without hesitation and it had a great run yesterday so I know it’s not the battery as the car didn’t even try and turn over. Feels like it’s electrical. Any ideas if anything like this may have common things to check?

Update : came back after shopping this morning, just thought I’d try and start it, it started without issue just showing some stability/run flat crap inoperative.


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[Blobcat]

I’d check the battery voltage initially with a meter, just to check its >12.4v

 

[malcolm E53 AMG]

The garage really need to read the codes present. If it’s nothing obvious with the wiring using the OBD2 port you can check the CANBUS for faults if necessary:

 

[DSK]

A handful of times I’ve returned to the car today and it’s started perfectly, (as I would usually expect it to). A couple of times the stability/run flat crap has stayed on, but, the infotainment appears to be working again consistently.


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[malcolm E53 AMG]

How old is the battery?

 

[DSK]

On the car when I bought it but it’s perfect as I’m not adverse to changing them for the sake of it.

Starts up every week with the eagerness of a new battery, which even I’m surprised at! battery test at MOT a few weeks ago was ‘very healthy’. I know batteries can do odd things but, coupled with the stability/tyre pressure crap which is pretty constant I have concerns, especially as it starts with telepathy like instant the moment the key is turned.

MB centre said they would come out Monday so all the above that’s been mentioned I will ask them to check etc.


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[Botus]

as blobcat says - likely they ran you out of volts - these cars go mad in any random strange manner whenever they like, if the volts aren't tip top

this next bit I doubt 100% is your issue - as u had the comand go odd too - but its worth knowing about. These cars have a huge penchant for many faults all the time, so getting two unconnected ones together must be seen as possible - in the summer a 4 year old ABS sensor went wrong and this 30 minute to fix fault can cause the whole car to go mad - I got ESP failure message, but as I pulled up it wouldn't go into gear forwards or backwards when I went to reverse on to a mates drive - just left me beached blocking the entire road (NICE), power steering goes in and out of stupid, gear changes, once I'd key on and off'd to find a gear to drive in, failed to behave and various lies of doom come up on the dash

 

[DSK]

18/11/23 - car started after several insert/remove key and turn attempts.

19/11/23 - as above and I took it for a 20mile spin.

MB centre owner came out (thanks to him), the car as Sod’s Law has it, worked perfectly…

Several thorough tests were run with that specialist xentry kit, after running, the cars battery was at 12.2v which, is not what they would expect. Amazingly it fires up up with telepathy like instant-ness which wouldn’t suggest a weakening battery on its own. Conclusion was the existing battery could have developed a bad cell or, have just been run low during the work which lasted between 8:30-3:30.

New Merc battery (Varta label) and key fob batteries in, about an hours worth of testing and clean bill of health.


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[peterws1957]

18/11/23 - car started after several insert/remove key and turn attempts.

19/11/23 - as above and I took it for a 20mile spin.

MB centre owner came out (thanks to him), the car as Sod’s Law has it, worked perfectly…

Several thorough tests were run with that specialist xentry kit, after running, the cars battery was at 12.2v which, is not what they would expect. Amazingly it fires up up with telepathy like instant-ness which wouldn’t suggest a weakening battery on its own. Conclusion was the existing battery could have developed a bad cell or, have just been run low during the work which lasted between 8:30-3:30.

New Merc battery (Varta label) and key fob batteries in, about an hours worth of testing and clean bill of health.


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Glad that the problem seems to have been sorted. Even a slightly defective battery can throw weird faults on an MB. I wonder whether sat in the workshop being serviced for several hours doors were left open and/or the sound system was left on causing the battery to drop below optimum level. I've seen this happen at dealers (not just MB) whilst waiting for a car to be ready and have wondered how many owners have had a similar problem to yours.

 

[DSK]

Yes the owner said this was likely as electric still operate and these things are hungry for electrics even if the infotainment is off.

I did think battery but, was confused why the car would then start later without any struggle but when it failed, there was no crank etc etc etc.

Despite my brakes issue with MB, credit to the owner for coming out and sorting it on the drive and doing it thoroughly!


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[EmilysDad]

Glad that the problem seems to have been sorted. Even a slightly defective battery can throw weird faults on an MB. I wonder whether sat in the workshop being serviced for several hours doors were left open and/or the sound system was left on causing the battery to drop below optimum level. I've seen this happen at dealers (not just MB) whilst waiting for a car to be ready and have wondered how many owners have had a similar problem to yours.

I didn't have a further problem, but years back when MB faffed about with the suspension of my R Class, I had to go back into the dealership to get them to jump start my car ..... I can only assume as you suggested .... multiple starts, radio on etc

 

[DSK]

Car has been good all week, no starting issues, no random fvcked up warnings.

Today, drove to Warwickshire. When coming back, no crank/no start when turning the key to fire it up. Took a bout two minutes of locking/unlocking, key in/out, swear at it, until it fired.

It’s now been stood for about 2 hours. I tried starting it several times with both keys and no difference. I did a quick test using a battery tester and the battery, with the engine off is at 12.6v. Is this too low? Is this new battery duff?

Whilst I will call the MB Centre on Monday, it will be be a case of diagnostics. To save me being taken for a ride, has similar happened to others on this era of Merc? E.g How does the ignition actually work and talk to the key etc? Do these keys become faulty etc?

This doesn’t make sense as I don’t see what they could have touched during a service a plus extra dsk bits to make it a proper ‘service’ but, the issue has only started happening after the service.


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[tode]

12.6V is fine (mine is OK with 12.2 - 12.3 V.

It's the same with both keys ?

 

[DSK]

12.6V is fine (mine is OK with 12.2 - 12.3 V.

It's the same with both keys ?

As per the post, tried both keys and exactly the same. When MB centre came out and changed the battery I also had the batteries in both keys replaced.

I tried Googling for some insight but, this seems to be common with many Mercedes with all sorts of variables such as the following just to mention a few;
Gear selector
Eis
Sam
ECU
Etc

Seen several bits and pieces online where people (albeit USA based) were told the diagnostics pointed to the likes of a sam/ecu etc and after changing those, it did not resolve the issue.

I’m going to try starting again later this morning and if doesn’t start then I’ll try charging the battery and try again as feel I have nothing to loose but, the car has been epic since I bought it 2 years ago.

Rather than spend thousands and have someone throw parts at it, (which is what I fear will happen now with MB centre) and not fix it, I’d rather pay someone like @AlexForti to come up for a day and take it from there.

(I am quite ****ed off as this car is only on 60k legit, and in the 10k I have done over the last 2 years, with both services done to my standards which are recorded as a sevice a and then some!, unmarked condition, solely run on vpower diesel etc, this car is epic and laughs in the face of what what 99% of folks call ‘mint/maintain regardless of cost’). I bought it to keep and maintain it to dsk standards but, really can’t be dealing with this crap and risk being stranded, helpless with a very young child).

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[tode]

The only thing I can think of that you can check yourself are the earth connections - see if there are any lose connections, starting from the battery.

If you find nothing amiss, then it's off to MB or an Indie for a session on Star.

I know it's a pain in the rear when a nice car plays up, but cars nowadays are such a crafty mix of mechanics, electronics and optics that any fault can leave you stranded.

 

[DSK]

Personal log;

17/11/23
Car serviced service A, gearbox service and change the front discs and pads for new ones as per my other brakes thread.
Stability and run flat warnings appear on the way to nursery.
Switch on/off at nursery, the warnings went went away and returned later.

18/11/23
Car failed to crank/start, I gave up after 20 or so attempts over approx 30 minutes.
Car shows run flat indicator inoperative and stability warnings.

Car started later in the evening without issue.

19/11/23
Car failed to crank/start for about 9 attempts.

20/11/2023
MB centre ran some diagnostics with xentry, didn’t find anything blindly obvious but saw the battery at 12.2v so fitted a new battery.

21/11/2023 - 25/11/2023
Car starts and runs fine, no warning messages about run flat / stability. Used the car locally for a few miles but ensured it was on for at least 20 minutes before switching off.

25/11/2023 evening

Car again fails to crank/start. Several repeated attempts and it fires and drives great back to a Nottingham from Warwickshire.

After parking up at home for 2 hours I try and start the car to see if the issue occurs, it does and the car fails to crank/start, despite trying for about a total of about 30 minutes over a further 2 hour period, with both keys. Run flat inoperative and stability control warnings re-appear. Battery showing 12.6v.

26/11/2023

As per the last bit above, car fails to crank/start, with both keys and displays the run flat and stability warnings present.

Battery is at 12.55v
The terminals are secure as recommended above.

Put the car on a hefty Noco charger for 2.5hrs and still no difference. So this now rules out the battery.

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[tode]

IMHO, I think you can rule out the battery . . .

 

[DSK]

IMHO, I think you can rule out the battery . . .

I would like to think so especially as when MB centre came last week, the car started perfectly on the original battery. It just doesn’t make sense as the car has been epic and I don’t see what they could have done during a service for this to start happening, aside from spilling one’s coffee onto some electrics etc.


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[malcolm E53 AMG]

Does sound temperature related and probably a bad connection somewhere I remember watching a Diagnose Dan session on YouTube with a similar intermittent fault which turned out to be a bad ECU for the gearbox. In your case the ignition unit needs checking for continuity when the fault occurs so it might be better to leave it with MB for a few days to do this

Just to add I had a similar fault with my S210 and it turned out to be a dry connection on the back of the ignition unit the connecting spades had oxidised and weren’t providing a good enough contact

 

[ajlsl600]

as blobcat says - likely they ran you out of volts - these cars go mad in any random strange manner whenever they like, if the volts aren't tip top

this next bit I doubt 100% is your issue - as u had the comand go odd too - but its worth knowing about. These cars have a huge penchant for many faults all the time, so getting two unconnected ones together must be seen as possible - in the summer a 4 year old ABS sensor went wrong and this 30 minute to fix fault can cause the whole car to go mad - I got ESP failure message, but as I pulled up it wouldn't go into gear forwards or backwards when I went to reverse on to a mates drive - just left me beached blocking the entire road (NICE), power steering goes in and out of stupid, gear changes, once I'd key on and off'd to find a gear to drive in, failed to behave and various lies of doom come up on the dash

Same as that!!!! Gone, for now when wss changed?