SBC possible failure advice please

[TennesseeJack]

I have all of a sudden the dreaded red light on my dash and left with reduced braking power only while out driving this week, luckily I was only doing about 10MPH at the time it happened. Being less than a mile from home I managed to get back ok.

The car in Question is an SL350 and is ten years old and is just approaching 40K miles.

I have checked the brake fluid and the level (recently serviced) is just above the maximum, I also have an ICARSOFT scanner i980 that I have used before on the car to check codes and it has read the following codes

C25D4 no pressure
C26EF Test voltage supply (circuit 30) of component A7/3m1 (high pressure charge pump)

C233D, C22BC, C23BD, C223C no pressure at wheel.

I am assuming I will need a new SBC pump? or have the faulty one repaired?
can anyone recommend a company to refurbish the SBC pump?

I would be grateful for any advice or help on this matter.

Kind Regards

 

[pmcgsmurf]

A 10 year old should not have SBC?

How's the battery and voltage when charging/not charging?

 

[TennesseeJack]

A 10 year old should not have SBC?

How's the battery and voltage when charging/not charging?

Thank you for the quick response

Battery voltage on the rear consumer unit is 12.1 Volts engine off and when charging engine running 14 Volts.
Battery voltage on the front starting unit is 13.1 Volts engine off and when charging engine running 14 Volts.

 

[TennesseeJack]

The vehicle (R230) was first registered in March 2009 and is the facelift model.

 

[TennesseeJack]

I could hear the pump pressurizing before when switching the ignition on or at various times but I can no longer hear it working following the brake failure.

Part number is SBC A 006 431 33 12 01 (this is taken from a sticker on the pump).

 

[grober]

del

 

[pmcgsmurf]

Does seem like a part number for SBC unit, thought they had gone by 2009.

Need an expert to come along who knows SBC.

Assume the batteries are all fairly recent as these can cause all sorts of errors.

 

[whitenemesis]

IIRC the SL kept SBC up to 2011

One can purchase new pumps direct from Bosch. MB dealerships are also selling these a slightly better prices these days, I believe even doing exchange units?

Give the dealership a call, nothing to loose.

 

[TennesseeJack]

Thanks pmcgsmurf for your help

The batteries appear to be fine and all other consumers of the battery on the car are working well. I thought the SBC was fitted to the SL model until 2011 unfortunately my post count is to low to post a picture of the pump.

 

[grober]

IRRC there was a software counter on these pumps that disabled them after a fixed no of applications. This could be reset via software to extend the life of the pump as a one-off fix. This was the case on the early pumps don't know if it applies to the later ones? lots of references to this online usually with reference to the early W211 which shared the same system.
Resetting the W211 SBC counter

 

[pmcgsmurf]

The batteries appear to be fine and all other consumers of the battery on the car are working well.

Always worth replacing the batteries if they are old, especially if the car is not used a lot.

 

[whitenemesis]

IRRC there was a software counter on these pumps that disabled them after a fixed no of applications. This could be reset via software to extend the life of the pump as a one-off fix. This was the case on the early pumps don't know if it applies to the later ones? lots of references to this online

STAR will interrogate the pump and if it's not faulty it will extend application count, so long as it hasn't been reset (by non STAR software) or extended before.
The extension in application count came from years of in service use reports and MB recognised they had set the initial count very conservatively (understandably)

 

[TennesseeJack]

Thankyou all for your replies and help

I don't think its the software counter as if has failed completely and I think you could still use the brakes with the software counter dash warning.

Yes the car is not used very often and I am happy to get and change the batteries. I have contacted my Indie and they are getting a price for a replacement pump for me they have star and will be able to programme the new pump to the car. I will report back on the price offered.

Regards
Mark

 

[whitenemesis]

I don't think its the software counter as if has failed completely and I think you could still use the brakes with the software counter dash warning.

I don't believe so, what would be the point of having a limit and then letting the driver ignore it?
Get the car to your indie and get the codes read using STAR

 

[Gbrowncls55]

IRRC there was a software counter on these pumps that disabled them after a fixed no of applications. This could be reset via software to extend the life of the pump as a one-off fix. This was the case on the early pumps don't know if it applies to the later ones? lots of references to this online usually with reference to the early W211 which shared the same system.
Resetting the W211 SBC counter

Thats true but at 40k is unlikely to have been exceeded and the icarsoft will give a specific code relating to "actuation limit exceeded" or something like that. Had a new one put on my wifes sl for that reason about 2 months ago. About £1200 at an indie inc fitting etc.

 

[TennesseeJack]

My local indie have priced me £1800 for a refurbished unit and fitting this also included the VAT, they would have been useful as they are only a mile from where the car is garaged.

I am going to get a few prices elsewhere as their price was only for a refurbished pump and not a brand new one.

Many thanks for all of the help and advice.

 

[AMGeed]

Maybe worth a call to this guy

https://www.ecu-repair.co.uk/product-page/sbc-pump-refurbish-service-by-post

 

[Dryce]

I don't believe so, what would be the point of having a limit and then letting the driver ignore it?
Get the car to your indie and get the codes read using STAR

There's no logical reason to disable the SBC components when the limit is reached. The point of the limit is to provide a warning that the component should be replaced - but that doesn't mean you kill the braking system. So if you were going to switch of the brakes you'd be better not allowing the car to be started once the limit was reached. And it might seem logical to give a proper warning some time prior to expiry.

 

[whitenemesis]

IIRC the dash will show a white message for a period of time, changing to red when the limit is reached. There are extremely few accounts on the web of SBC brakes failing. I know of one where brakes dropped to the 10% emergency level whilst driving at low speed. Considering how many SBC equipped taxis were in operation at one time ...

 

[grober]

Looking at the fault codes again this caught my eye
C26EF Test voltage supply (circuit 30) of component A7/3m1 (high pressure charge pump)
might indicate that the voltage supply to the SBC Pump has failed. I believe as part of a vital safety system the pump may have one or more permanently live voltage supplies possibly from the underbonnet prefuse unit- might be worth checking if any of those are blown. They could have blown due to pump failure of course but worth a check? Unfortunately I have no ready access to a circuit diagram at this point.