Deadly SBC failure - warranty extension in USA and Canada

[LostKiwi]

the only benefits of my fathers car with SBC is

1) odd brake pedal feel,
2) odd noises from the module
3) a stupid penchant to stand on the brakes when you don't want it too (because the current drivers reaction time isn't as slow as many drivers they clearly thought needed help)

never had any of those issues on a car with conventional servo assistance

And I have never had any of those issues. In fact quite the contrary.
Pedal feel has always been excellent, it's never tried to stand on its nose (except once where I asked it to and it stopped in an amazingly short distance). As for the noise it doesn't bother me - it's just another feature and inaudible from inside .


Conversely when pressing on a few times in a conventional vehicle and left fort braking I've had the odd scary moment where servo assistance wasn't present when expected and was there when not expected!

I've also had a diaphragm in the servo fail and on one car a seal on the master cylinder allowed the servo to fill with brake fluid which then released vast clouds of white smoke out the exhaust as the fluid was sucked into the inlet manifold. I've also had a vacuum pump on a diesel car fail with no warning.

 

[flowrider]

SBC has some benefits such as keeping the discs and pads dry in the wet and hold function when stationary. It's a great braking system as long as it is maintained properly. Considering the number of owners of cars with SBC I think the few issues reported cloud what is a good system, a bit like ABC suspension.

 

[AMGeed]

And I have never had any of those issues. In fact quite the contrary.
Pedal feel has always been excellent, it's never tried to stand on its nose (except once where I asked it to and it stopped in an amazingly short distance). As for the noise it doesn't bother me - it's just another feature and inaudible from inside .


Conversely when pressing on a few times in a conventional vehicle and left fort braking I've had the odd scary moment where servo assistance wasn't present when expected and was there when not expected!
.

As above, I would suggest you have your fathers SBC checked by a good indy if he is experiencing any of those issues.

With my SBC, the pedal feel was perfect.
If you stamp on the brakes you'd stop very suddenly with no dramas. Its brilliant system with the only flaw being the pump should be considered a consumable part.
The pump can be noisy and as you know is only priming for the next cycle.

 

[Philedge]

the only benefits of my fathers car with SBC is


3) a stupid penchant to stand on the brakes when you don't want it too

One of SBCs features is to pre empt the need for an emergency stop if the throttle is lifted rapidly, and pre charge the brakes. If the brake pedal is then "jumped on", SBC assumes the need for an emergency stop and slams the brakes on until the driver backs off the brake pedal. Maybe you or your dad are being a bit rough with the throttle/brakes and activating this feature??

 

[Botus]

One of SBCs features is to pre empt the need for an emergency stop if the throttle is lifted rapidly, and pre charge the brakes. If the brake pedal is then "jumped on", SBC assumes the need for an emergency stop and slams the brakes on until the driver backs off the brake pedal. Maybe you or your dad are being a bit rough with the throttle/brakes and activating this feature??

Thank you, I know what the feature is. I just don't want it dangerously interfering with my day to day driving...

If I want to stop quickly I press the pedal hard. Unlike the users merc built the system for, I do not need a computer wrongly interpreting my quick reactions and covering the brakes (to gently work around to another road users incompetence) activating the ABS.

 

[Blobcat]

Thank you, I know what the feature is. I just don't want it dangerously interfering with my day to day driving...

If I want to stop quickly I press the pedal hard. Unlike the users merc built the system for, I do not need a computer wrongly interpreting my quick reactions and covering the brakes (to gently work around to another road users incompetence) activating the ABS.

So your method of driving is not braking then stamping in the brake? Do you replace many rear bumpers?

If you have to stamp on the brakes then you’re reacting to an immediate threat. SBC (or later OBC) is then helping you by reacting to your input and getting the car to brake as hard as it can. Reasoning is that in emergency situations people brake hard then lift slightly so giving a much longer braking distance thereby increasing the likelihood of an accident. SBC or OBC take away that “lift”

Your method of driving isn’t one as advocated by the IAM or ROSPA

 

[Conor]

This is very interesting.. subbing to this thread.

Admittedly, I haven't read the last 2 pages of this thread but I will circle around.

Now... the pertinent question is the significance of all of this on non 212 models such as the CL, SL etc..

(my interest in the SL obviously)

 

[bob 6600]

SBC was phased out in 2006 on the W211 (06-06) so face-lift cars didn't have it. IIRC it was also phased out of other models too. From reading posts of SBC equipped owners, the braking system was very very good however the cost of replacement when the first lot reached their set number of presses was north of £1500. It is much more reasonable now.

The US/Canadian articles are not new and it's not the only issue they will pay out for there (W211 fuel tank on E55k is another). However, in this country, MB aren't interested because they know they can get away with it.

 

[flowrider]

This is very interesting.. subbing to this thread.

Admittedly, I haven't read the last 2 pages of this thread but I will circle around.

Now... the pertinent question is the significance of all of this on non 212 models such as the CL, SL etc..

(my interest in the SL obviously)

This thread is as pertinent to the SL as it is to the E and CL vehicles.

 

[Conor]

This thread is as pertinent to the SL as it is to the E and CL vehicles.

My thoughts exactly... So I'm wondering how if I'm suddenly going to lose breaks.

I am aware of the dash warning and general count down to 0 but wondering about other issues.

I guess it is what it is and will put it down to the cost of R230 ownership.

 

[LostKiwi]

My thoughts exactly... So I'm wondering how if I'm suddenly going to lose breaks.

I am aware of the dash warning and general count down to 0 but wondering about other issues.

I guess it is what it is and will put it down to the cost of R230 ownership.

You don't suddenly lose brakes unless you ignore the first warning.
The first warning in white is 'Service Brake - visit workshop'
This tells you you have reached the SBC pump actuation limit and the pump needs to be checked. If the actuation count has not been hit previously and updated to the revised count MB used for later cars it can be adjusted to the newer car limit. If it has hit the higher limit the pump needs to be replaced. If it's on the lower value the warning occurs at around 100k miles but can occur earlier or later depending on driving style and usage profile (motorways will give a higher distance, town usage a lower distance).
If this is ignored or if the counter is disabled (eBay kits available to do this) eventually the brushes in the motor will wear out and the white warning will be replaced with a red one. At that point you have zero assistance and will need to press the pedal a LOT harder but you will still have some braking available.
Botus is scaremongering using old stories from the US. Be aware of what may happen by all means but don't be scared of it. Treat the warnings with due respect and you will be fine.
Our 230 has last month come up with the white warning (107k miles). Brakes still work perfectly. I'm going to take a look using Star (requires developer mode which I don't currently have) to see what the count is. I'll also remove the motor cover to verify brushes. If the count is the early value and the brushes are ok I'll reset it to the later one and go from there. Otherwise it will be sent to JohnnySBC for refurb.

 

[Conor]

You don't suddenly lose brakes unless you ignore the first warning.
The first warning in white is 'Service Brake - visit workshop'
This tells you you have reached the SBC pump actuation limit and the pump needs to be checked. If the actuation count has not been hit previously and updated to the revised count MB used for later cars it can be adjusted to the newer car limit. If it has hit the higher limit the pump needs to be replaced. If it's on the lower value the warning occurs at around 100k miles but can occur earlier or later depending on driving style and usage profile (motorways will give a higher distance, town usage a lower distance).
If this is ignored or if the counter is disabled (eBay kits available to do this) eventually the brushes in the motor will wear out and the white warning will be replaced with a red one. At that point you have zero assistance and will need to press the pedal a LOT harder but you will still have some braking available.
Botus is scaremongering using old stories from the US. Be aware of what may happen by all means but don't be scared of it. Treat the warnings with due respect and you will be fine.
Our 230 has last month come up with the white warning (107k miles). Brakes still work perfectly. I'm going to take a look using Star (requires developer mode which I don't currently have) to see what the count is. I'll also remove the motor cover to verify brushes. If the count is the early value and the brushes are ok I'll reset it to the later one and go from there. Otherwise it will be sent to JohnnySBC for refurb.

Interesting thanks. To be honest most of what you have explained was my understanding of the issue to date.

I just wasn't sure if the linked articles were relating to something new or old.

It is interesting that you nerd developer mode to just read a value of something. I though dev mode was for more write/program oriented tasks.

Assuming that while dev mode is needed that doesn't you mean you need SCN, which if I understand is just for coding modules. Assume you would need SCN if you want to update the count to revised number?

 

[LostKiwi]

I don't think SCN is required to update the count.

 

[Botus]

If you have to stamp on the brakes then you’re reacting to an immediate threat. SBC (or later OBC) is then helping you by reacting to your input and getting the car to brake as hard as it can. Reasoning is that in emergency situations people brake hard then lift slightly so giving a much longer braking distance thereby increasing the likelihood of an accident. SBC or OBC take away that “lift”

the feature we are discussing here is not activated by to how smoothly (or not) one drives... On the 2006 era E class with ABC (like many) it activates the ABS because it detects the speed with which you change from Throttle open to Brake light coming on. It is NOT related to how much braking input the driver is using.

Sadly we allow so many poorly trained, ill-informed and incapable drivers on our roads, that car manufacturers looking at accident data realised MOST drivers never give enough braking input in an emergency to avoid MANY easy avoidable accidents. So they decided they could help. However the way they did it on early cars was poorly implemented.

If the speed of change from throttle to brake is faster than X apply full brake pressure to the pedal (which will likely activate ABS)
until any braking effort instigated by the driver is no longer there.

Thus if a good driver reacts promptly to even a minor issue (say you just want to add a meter of extra room the around the fool who has suddenly and unnecessarily entered into your safety zone / road space) a driver may be forced to overcome a destabilised car and potentially inconvenience other road users because Mercedes Benz engineers thought jamming on the ABS would be helpful.... even though the driver NEVER wanted and NEVER asked for "any assistance"....

And as I think you'll be starting to understand..... I have NEVER had this problem on ANY other brand of car and have been using vehicles with ABS for around 30 years and ESP ones for around 12 years

 

[Blobcat]

the feature we are discussing here is not activated by to how smoothly (or not) one drives... On the 2006 era E class with ABC (like many) it activates the ABS because it detects the speed with which you change from Throttle open to Brake light coming on. It is NOT related to how much braking input the driver is using.

Sadly we allow so many poorly trained, ill-informed and incapable drivers on our roads, that car manufacturers looking at accident data realised MOST drivers never give enough braking input in an emergency to avoid MANY easy avoidable accidents. So they decided they could help. However the way they did it on early cars was poorly implemented.

If the speed of change from throttle to brake is faster than X apply full brake pressure to the pedal (which will likely activate ABS)
until any braking effort instigated by the driver is no longer there.

Thus if a good driver reacts promptly to even a minor issue (say you just want to add a meter of extra room the around the fool who has suddenly and unnecessarily entered into your safety zone / road space) a driver may be forced to overcome a destabilised car and potentially inconvenience other road users because Mercedes Benz engineers thought jamming on the ABS would be helpful.... even though the driver NEVER wanted and NEVER asked for "any assistance"....

And as I think you'll be starting to understand..... I have NEVER had this problem on ANY other brand of car and have been using vehicles with ABS for around 30 years and ESP ones for around 12 years

What you’re describing is lack of planning and forethought on the driver, if you need to react that fast to someone pulling across into your safety buffer then you’re too close to the vehicle in front and SBC is doing its job as designed. You really are raging against the machine and I worry for your blood pressure.

 

[LostKiwi]

This feature you're moaning about exists in non SBC cars too. I first encountered it on W202 C Class and it's also fitted to my 210 and Smart Roadster and is called electronic brake assist. On these it measures the rate of pedal depression and will apply full braking force to activate ABS.
However....
I have never had what you describe on my SL or 210. I did encounter it in my Smart when first purchased as it had long brake pedal travel due to rear drums not being adjusted correctly. When doing a pre-pump of the brakes when pulling up at a junction I inadvertently hit the threshold and it stopped very quickly!

Your contention that a good driver reacts rapidly to a minor issue is flawed.
A good driver anticipates events and will have reacted appropriately before an issue occurs. This rarely means rapidly coming off the throttle and onto the brake as normally they would have been off the throttle long beforehand having recognised a potential issue in the making.
When pressing on in the SL I am frequently transferring between power and brake but again a good driver does this smoothly so as to maintain the vehicles balance and composure on the road. If you look at telemetry for F1 drivers you rarely see sudden inputs in throttle or brake.

If you are regularly encountering issues with electronic brake assist it suggests your inputs are not conducive to smooth driving and I'd certainly not want to be a passenger!

 

[McDonald]

If you are regularly encountering issues with electronic brake assist it suggests your inputs are not conducive to smooth driving and I'd certainly not want to be a passenger!

From the temperature of conversations between you and Botus, he's unlikely to ask you out on a date.

 

[Botus]

I guess the ones saying I don't react early enough aren't motorcyclist still alive after 40 years riding bikes …. every ride you have to save your own life avoiding cretins in car's who don't even know how to look out of the windows

a side effect is you learn to work out what the retards are going to do (before they even know) and react very quickly

something the factory hadn't factored in their maths.... (5 mins 53 seconds !!!) I find it odd most other manus do

 

[LostKiwi]

I suspect you react quickly enough but I question if you anticipate well enough.
Different things entirely.
Cars are also very different to bikes (and I'm not a motorcyclist - I want to keep my organs thanks).

 

[SL63 Mark]

For what it is worth, I am happy with my SBC (Sensotronic Brake Control) I like the feel it gives, it can stop in incredibly well in an emergency, and I have never had any trouble with it. Personally I think it is one of the quirky features I enjoy about these cars, if I wanted a straightforward car I would buy a three series (oh wait I have one).