S205 Service Reset to A0 During Aux Battery Fault

[Beastlee]

Hi All, I bought an S205 C250d at the start of April from a 3rd party dealer. The car is a September 14 model and was high mileage, 61K, but was one owner and advertised with full MB history. It was due the B3 service so a service was agreed in the sale, they did it themselves before I knew it and reset the counter to A4. I still haven't had supporting paperwork but that's another story (you'll learn I'm good a those)!

There were also a couple of issues I agreed with the garage which included a replacement of the auxiliary battery and this was done a month later. I've had consistent problems since but on the 1st August the red Auxiliary Battery Malfunction alert came up so I took the car back to them. They finally took a look at it in early September and their 'specialist' confirmed a faulty aux battery unit a week later. I got the car back whilst they booked it into Mercedes and I found that the service counter had been reset to A0 and no longer showed the mileage to the next service, just a number of days. I've already done 7000 miles in it and I recall it saying something like 10500 miles to next service and it should be due circa 25th March but it currently thinks A) is due in 217 days, 25th April.

To cut a long story long, can the counter be reverted to the A4 state, with the correct days and at least something resembling the correct mileage to next service? Also, should I be worried that they were even able to reset it to A0? I've already told them I'm pretty much forced to service it again now, so I can ensure it's been serviced properly and know when it is really due. I finally get it back today, after a steering rack replacement, and this is the last outstanding issue.

 

[ernie]

Hi All, I bought an S205 C250d at the start of April from a 3rd party dealer. The car is a September 14 model and was high mileage, 61K, but was one owner and advertised with full MB history. It was due the B3 service so a service was agreed in the sale, they did it themselves before I knew it and reset the counter to A4. I still haven't had supporting paperwork but that's another story (you'll learn I'm good a those)!

There were also a couple of issues I agreed with the garage which included a replacement of the auxiliary battery and this was done a month later. I've had consistent problems since but on the 1st August the red Auxiliary Battery Malfunction alert came up so I took the car back to them. They finally took a look at it in early September and their 'specialist' confirmed a faulty aux battery unit a week later. I got the car back whilst they booked it into Mercedes and I found that the service counter had been reset to A0 and no longer showed the mileage to the next service, just a number of days. I've already done 7000 miles in it and I recall it saying something like 10500 miles to next service and it should be due circa 25th March but it currently thinks A) is due in 217 days, 25th April.

To cut a long story long, can the counter be reverted to the A4 state, with the correct days and at least something resembling the correct mileage to next service? Also, should I be worried that they were even able to reset it to A0? I've already told them I'm pretty much forced to service it again now, so I can ensure it's been serviced properly and know when it is really due. I finally get it back today, after a steering rack replacement, and this is the last outstanding issue.

The service interval for these is 12 months or 17500 miles, whichever is first. If you are not confident that it has been serviced properly, I would have it checked/serviced by a recommended MB Indy. Is there any record of the autobox having been serviced?

Sorry, can't really help with the counter, but the reset may have happened as a result of the battery change.

Ernie

 

[rf065]

The service interval for these is 12 months or 17500 miles, whichever is first

I think 15,500 miles or 12 months is correct. You can set it as often as you like but I don't think disconnecting the battery will change it.

 

[markjay]

I think 15,500 miles or 12 months is correct. You can set it as often as you like but I don't think disconnecting the battery will change it.

As above, disconnecting the battery will not in itself reset the ASSYST Plus service indicator.

The garage may have unintentionally reset the service indicator.

But.. ASSYST can be unreliable, on mine the 'next service' changed on it's own after a few months for no obvious reason.

Go by what needs to be done:

Mercedes-Benz UK | Electronic Service Sheet

..in conjunction to what has actually been done so far:

Mercedes me assist

(Digital Service Record - requires Mercedes Me account)

 

[Beastlee]

Thanks folks. Turns out they literally just did an oil and filter change. I was originally looking at a service plan as the next service needs the autobox doing. It looks like I'm going to book it in to a local indy as there's already done so much non-mb work on it and I guess the indy will still be better value with the autobox.

It's cost them £3k to get the car to the current state so I'm not going to push them any further. I'll just get the indy to service it next month and then the next service reset will be back where it should be. It needs two new tyres due to the rack issue so it's going to be an expensive 6 month point of ownership.

Now to find a good Indy near Blackpool/Preston.

Sent from my SM-G930F using Tapatalk

 

[Beastlee]

As above, disconnecting the battery will not in itself reset the ASSYST Plus service indicator.

The garage may have unintentionally reset the service indicator.

But.. ASSYST can be unreliable, on mine the 'next service' changed on it's own after a few months for no obvious reason.

Go by what needs to be done:

Mercedes-Benz UK | Electronic Service Sheet

..in conjunction to what has actually been done so far:

Mercedes me assist

(Digital Service Record - requires Mercedes Me account)

Thanks, for this. I have a Mercedes Me account and it lists the three original services but shows last service due back in May. I read that Indys can upload services to this if they have have the right kit. Is this true? I've 350 days of mobilio left but I have AutoAid so not too worried about losing it in a year.

Sent from my SM-G930F using Tapatalk

 

[markjay]

Thanks, for this. I have a Mercedes Me account and it lists the three original services but shows last service due back in May. I read that Indys can upload services to this if they have have the right kit. Is this true? I've 350 days of mobilio left but I have AutoAid so not too worried about losing it in a year.

Sent from my SM-G930F using Tapatalk

Yes, any independent gagarge can access MB's central computer and update the service record, as long as they signed-up to this service with MB. This is due to EU's 'Bloc Exemption' for the automotive industry (though it may change after Brexit).

 

[markjay]

PS - while independent garages can update the Digital Service Record, only the dealer service provides Mobilo cover and continuation of the anti-rust warranty.

So if the last service was done by an independent garage, then the car won't have Mobilo (or anti-rust warranty) anyway, i.e. regardless of whether the Digital Service Record was updated or not.

 

[Beastlee]

Thanks again guys. By resetting the counter to where it was before the A0 reset the car now shows mileage to service as 14K, I'll be doing it much sooner. The car is now back and all fixed except for the Start/Stop that seems to be temperamental, even after a 700 mile motorway drive. I'm not too worried as I've seen this on posts everywhere, it would be nice if Mercedes included something to indicate why it's not ready!

 

[markjay]

So what's the next service now? Still A0?

 

[markjay]

Re the Stop/Start, was the car checked with STAR for fault codes?

 

[Beastlee]

So what's the next service now? Still A0?

Without double checking I think it's A4. They basically did a quick succession of service resets to bring it back in line.

Re the Stop/Start, was the car checked with STAR for fault codes?

It went into MB Blackburn for diagnostics and then had the Aux battery replaced by an independent (non MB specialist) garage. It did work on Monday evening for the first time and was still OK Tuesday morning but since Tuesday afternoon it just sits yellow again. I've done another 100 mile round trip and nada, even with a large amount of charging time. WHen they first replaced the aux battery and the starter battery under the bonnet it worked well for about 4 days then went to yellow, that was before the Aux batt failure.

 

[markjay]

So they replaced both the main starter battery and the auxiliary battery? Were the new batteries original MB?

Also was the car scanned on STAR?

 

[markjay]

BTW my 2013 W204 is still on its original batteries (both main and auxiliary), and the ECO symbol on the dash goes from yellow to green within 5 to 10 minutes from cold start in the morning, so yours does not sound right.

 

[Beastlee]

Genuine aux battery module, old one had domed the capacitors so badly they caused a protrusion in the plastic casing 1cm tall.
Starter battery is an Exide 80AH unit, non MB but good quality.
Today I am going to use the workshop menu and monitor the battery rates. I suspect there may be a charging issue somewhere.

It's in for 2 new tyres Saturday and tracking next week, the garage that did the work on the suspension and steering didn't check it afterwards so both front outers have been destroyed in 7000 miles.

All in a terrible first experience with a MB despite being the newest car i have ever bought. Strange though, I still really like the car.

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[Beastlee]

Got the new tyres then informed I needed two more Next day I got a CEL warning and it looks like one of the NOx sensors has gone. Unfortunately I'm now over 6 months into ownership so it looks like I have a nice bill to pay as the garage won't even consider it. They had the car for 2 months of the original time and I didn't get the car back in a working state until a week before the 6 month point arrived so I'm more than a little annoyed about it. What's worse is that I was planning on getting MB warranty but was waiting until the dealer had given me the car back with the work done. It would have saved them the cost of the rack too!

 

[markjay]

According to some posts here, there's a chance that the NOx sensor MIL will go away if you switch to Shell V-Power Diesel (or potentially also to other premium Diesel fuels).

 

[Beastlee]

According to some posts here, there's a chance that the NOx sensor MIL will go away if you switch to Shell V-Power Diesel (or potentially also to other premium Diesel fuels).

I'm already running Shell diesels and I might try it for the next few fills, but at £1.55/litre and my mileage rate it wouldn't take long to cost more then fixing the dammn thing. It's booked into CVM in Preston in two weeks so I hope it's not causing further damage.