e270CDi Help

[Chris Plane]

Having bought this car 2005 estate I have always had a warning light on the dash "Service Brake - Visit Workshop". I haven't driven the car much (max 50 miles) since i've owned it as I knew it needed a few bits doing so I have been working my way through these.

I have never owned a Mercedes so was very unfamiliar with them when I bought it. I was told by the previous owner that this had been on for while and was a result of him fitting a new ABS ring. I knew no better at the time so accepted this.

Reading up on this and now having a iCarsoft scanner I have started to see what this is.

The fault code is:

C2495 check wake up procedure of control module A7/3n1 (SBC control module)

The live data shows the only odd thing I could see as follows:

053 wake up for N10/10 (Driver side SAM Control Module) shows initially 1.4v

This rises from 1.4v to 11.4v over time.

I have spoken to a local (18 miles away) Merc Indie and have agreed to take the car in in as i'm aware that the warning can be the SBC unit failing.

Two questions which I would appreciate any help with

1) does anyone have any idea or experience of what this might be other than a faulty SBC unit?
2) As I have no idea what the cycles are on the SBC unit and so have no idea if it anywhere near its end of life I am very unsure if i can drive it the 18miles to the indie. What happens if the unit fails? Will I literally have zero brakes and thus no way to stop the car?

Any help very much appreciated

 

[robin.large]

Hi. Not sure if it's relevant but I had similar messages on a 2013 SLK. Turns out it was a knackered auxiliary battery..

Sent from my ONEPLUS A5010 using Tapatalk

 

[Chris Plane]

Hi. Not sure if it's relevant but I had similar messages on a 2013 SLK. Turns out it was a knackered auxiliary battery..

Sent from my ONEPLUS A5010 using Tapatalk

 

[Chris Plane]

That's interesting. Could this be the auxillary battery being low that gives a low voltage to the SBC unit on startup causing the warning?

Will check the SAM front module for faults

 

[robin.large]

I didn't link the two initially. The low voltage and SBC problem was irritating but not a show stopper.
However my wife then complained that stop start had quit a while back. Usual issue for that was aux battery and sure enough at 6yrs old it had given up.
Fitted new aux battery, stop/start back in action and surprisingly the SBC fault disappeared..... Along with the associated low voltage warning..

Sent from my ONEPLUS A5010 using Tapatalk

 

[AMGeed]

I didn't link the two initially. The low voltage and SBC problem was irritating but not a show stopper.
However my wife then complained that stop start had quit a while back. Usual issue for that was aux battery and sure enough at 6yrs old it had given up.
Fitted new aux battery, stop/start back in action and surprisingly the SBC fault disappeared..... Along with the associated low voltage warning..

Sent from my ONEPLUS A5010 using Tapatalk

I didn't realise that a 2013 SLK was fitted with SBC? I thought it was phased out with the facelifted 2006 W211 E class.

Anyway, this guy can probably help the OP should the SBC pump need attention.

https://www.ecu-repair.co.uk/shop

 

[AMGeed]

That's interesting. Could this be the auxillary battery being low that gives a low voltage to the SBC unit on startup causing the warning?

Yes. I had SBC warnings on my previous E55 when the alternator failed. Low voltage brings up lots of spurious messages.

Make sure both batteries are reading at least 12.6v resting (fully charged)

 

[robin.large]

Sorry not SBC - stupid mistake! EPB and ASR codes/lights.
I think the point I was making is that MB are very sensitive to voltage in both main and auxiliary batteries.
If low voltage throws a safety code before or at startup then it may stay live even when voltage is restored when running.

Sent from my ONEPLUS A5010 using Tapatalk

 

[Chris Plane]

I didn't realise that a 2013 SLK was fitted with SBC? I thought it was phased out with the facelifted 2006 W211 E class.

Anyway, this guy can probably help the OP should the SBC pump need attention.

https://www.ecu-repair.co.uk/shop

Thankyou fir the link

 

[Chris Plane]

Yes. I had SBC warnings on my previous E55 when the alternator failed. Low voltage brings up lots of spurious messages.

Make sure both batteries are reading at least 12.6v resting (fully charged)

Will check that thankyou

 

[ajlsl600]

Note clear codes go again .if batt related there may be plenty. As above, if stop start works ,aux batt likely ok.
Disable stop start,I assume u have it ?at each start up saves u b,all and can bring about a number of expensive issues
I stand to be corrected but I believe star can provide info on cycles of sbc .

 

[00slk]

On my old E Class I to had this message and it was the SBC had timed out on the amount of times it was pressed for stopping. Does the brake hold work. Some SBC cars had this option with SBC.

 

[mioba]

get the codes read by a mechanic who understands. easy to misdiagnose, follow 20 suggestions, burn money and eventually by luck fix the issue.

 

[Chris Plane]

On my old E Class I to had this message and it was the SBC had timed out on the amount of times it was pressed for stopping. Does the brake hold work. Some SBC cars had this option with SBC.

No the SBC Hold wont work

 

[umblecumbuz]

As mioba above.
Get the Indie to scan it - hopefully he's got Star, but worth checking before you travel.
Otherwise, heed every suggestion and swap parts until you guess on the right bit!
The joys of Merc ownership.

When the 270cdi motor is running right, it's a glorious, rapid and frugal lump that you'll find impossible to wear out!

 

[John Laidlaw]

@JohnnySBC is your man.
SBC Hold inoperative is an issue I had with the 230 which I never resolved, just didn't bother using it. I changed the Consumer battery hoping that would cure the issue- it didn't and no codes were thrown up by Star so it remained a mystery. If I had kept the car I would have thrown even more money at it and replaced the SBC unit or refurb....

 

[John Laidlaw]

now if you were in the US......

 

[John Laidlaw]

Sorry, another question regarding your question reference driving the 18 miles.... is the warning message "Service Brake - Visit Workshop" white?

 

[Chris Plane]

Sorry, another question regarding your question reference driving the 18 miles.... is the warning message "Service Brake - Visit Workshop" white?

Yes it's white message. It can be cleared with iCarsoft MB v1. 0 but comes back on in about 30 seconds. Same code "wake up fault"

 

[Chris Plane]

This is it