Boulder GT3

Someone was asking me about the 211 brakes. They work fine and I've never had an issue. There's just that extra step when I put pads in...

At any rate, I'm sure I knew at one time but now I've forgotten. Why did Mercedes use the SBC system? What was the advantage? Thanks.

Diesel Benz

Perhaps you should print this for your friend:
http://www.mercedestechstore.com/pdf...%209-30-02.pdf

220S

In theory, brake-by-wire is a good system. But it's implementation was a different story. Although I'd put the blame more on Bosch than MB. Software failure (the ECU had issues) was the real problem.

But these days ESP and other advanced electronic assists has made a brake-by-wire system pretty much obsolete, so a combined conventional hydraulic system is more feasible, reliable, and less complex.

MB wasn't the only to use it (Toyota did, too) but MB was the first to use their invention (Sensotronic Brake Control) on cars commercially.

It's really unfortunate MB had issues early on, because it gave their system a bad name. It was way ahead of its time.

Mercedes cancels by-wire brake system; decision a blow to technology's future
By JENS MEINERS | AUTOMOTIVE NEWS
Mercedes-Benz is discontinuing the twice-recalled Robert Bosch GmbH braking system on the E-Class and CLS-Class sedans next summer in a move that is a blow to automotive brake-by-wire technology.

Mercedes will drop the Sensotronic Brake Control system from the E-Class in June 2006 when it introduces the car's midterm face-lift. At about the same time, the E Class-derived CLS also will lose the system. Both cars will have a conventional hydraulic braking system. "We can now offer all the comforts of SBC in a conventional system," said a Mercedes insider. "SBC was a very expensive system."

But the source also acknowledged that customers had lost confidence in the system.

The technology eliminates the mechanical link between the driver's brake pedal and the brakes, substituting an electrical link that actuates the brake calipers.

Customer complaints were linked to the failure of software for the brake system. When the system failed, the hydraulic system took over. But that resulted in a longer stopping distance and additional brake pedal effort by the driver.

"Statistically, (the Sensotronic Brake Control is) as good as our other braking systems and sometimes better," the insider said. "But we cannot get the doubts out of customers' heads."

Mercedes' SL roadster and the low-volume SLR McLaren and Maybach supercars will retain the brake system until the end of their life cycles.

It would be too costly to re-engineer those low-volume cars to accommodate a conventional system, a source said.

Sensotronic Brake Control was supposed to highlight Mercedes' technology leadership. Instead, it created a double blow to the brand's image.

In May 2004, Mercedes recalled 680,000 vehicles to fix the complex brake-by-wire system. Then, in March 2005, 1.3 million cars were recalled, partly because of further unspecified problems with the Sensotronic Brake Control system.

Bosch has no other customers for the system, which it co-developed over nine years with DaimlerChrysler AG at a cost of 147 million euros, or about $173.3 million at current exchange rates.

A Bosch spokesman acknowledged that the system has lost some of its competitive edge.

"In 2001 we were far ahead with SBC, but conventional technology has not been standing still," the spokesman said.

"With the ESP Premium (vehicle stability system), we have all SBC functions in a conventional system."

bigben320e

Great post. My SA was telling me about the SBC system and that it was ahead of it's time when I asked about it, as it is on my CLS.

lkchris

I'd take SBC on my GL in a heartbeat. About anything would be an improvement on the pathetic pedal feel on those models.

werewolf34

Maybe a less tubby car is in order

Boulder GT3

Thanks. That's more than I ever knew about it. I've had two Sl's with it and one E. I've never had an issue. The feel seems fine for the street although none of those cars are driven near the limit of braking.

This is another indicator to stay away from new technology for the first year.

220S

Just don't try any trail braking with a SBC equipped car. You'll get a bigger surprise than just weight transfer

Boulder GT3

IIRC, you track a 993 and I'm sure trail braking is a good friend.

Now you've raised my interest. I wonder what would happen in a 211 if I really wanted to plant that front tire on turn in....

Benz-O-Rama

My E500 and SL600 both have the SBC, while my R500 and C240 don't. I think I prefer the SBC in panic situations, as I've had a few close encounters with deer, but I hate the non-linear feel of them in stop and go traffic. They feel 'choppy' or 'grabby' for a lack of a better word.

Oddly enough, my non-SBC R500 has a brake/hold feature for inclines, while my SBC cars don't. Never could figure that one out.

Boulder GT3

I'm in the camp that likes fewer nannies on cars. The best brakes I've ever used were very simple with very good components.

Heel/toe, threshold braking, lane toss are soon to be lost skills.

K-A

My SBC is the most confidence inspiring braking unit I've ever experienced in a car for panic stops. However it sucks in traffic, I have always been a self proclaimed master at stopping cars smoothly, just can't get it right in my E, always a grabby, jerky stop. Stupid M-B said that they are supposed to "eliminate hard stops" or whatever, seems they should have trusted the driver more.

Boulder GT3

I finally got a chance to read this. Very sophisticated and interesting. CAN connections to the wipers? Very complicated. Also interesting that you don't get the pulse back through the brake pedal. Learn something new all the time.

It still strikes me as a cure for an illness I'm not sure I have.

Ronaldk

Repost from similar discussion topic, but of more relevance here: (apologies to those that have read it before...)

You may be interested to know that at least the "old" generation SBC has better performance than the breaks in the new (W212) E-class:

Break perfomance measured in seconds with stops from a speed of 100km/h (approx. 62 Mph) at 30 seconds intervals on a good bitumenised surface is:

W211 (model E 200 K - MY 2004) - best 2.72 seconds, worst 2.77 seconds and average of 10 stops = 2.75 seconds.

W212 (Model E 300 - MY 2010) - best 2.84 seconds, worst 3.13 seconds and average of 10 stops = 2.90 seconds.

Both vehicles tested with standard factory fitted tyres (for their respective MY). Source: Car Magazine Jul 2004 and Sept 2009 editions.

I certainly hope than W212 e-class does not drive behind me when I need to make an emergency stop!

gnma

I certainly hope you can make that emergency stop with your SBC equipped car. (Search for "SBC failures" and read up on how much little braking ability is available once SBC fails). At least the conventional-brake equipped
W212 car has brake reserve stopping capability. You and I do not....

Diesel Benz

How do you know he has equally much muscle in his legs as you do? The "reserve braking capability" is all hydraulic without any boost power but if you press the pedal with full power, you should have decent braking power although less than the traditional braking system at a brake booster failure.

220S

Yeah, I think the SBC "issue" just got really bad press, and then of course liability is also a big thing for any mfg. SBC is not an inherently bad system. It was (as are most of MB's innovations) way ahead of its time. But with the early SBC ECU glitches, it became a problem in consumers' minds and a problem for MB.

The later versions of SBC have been fine. It's still in the current SLs.

But even Bosch and MB admit that with the latest conventional electronic assist components, and ESP, etc.., it's not really cost effective to use and evolve the SBC concept anymore.

Hubi

DO YOU GUYS HAVE THAT "SHAKING" BRAKE PEDAL IN EVERY 4-5 TIMES YOU TOUCH IT?

Ronaldk

Hubi, if you are refering to the slight vibration during pressure build up then you may want to consider the replacemnet suction hose with improved dampers. Great improvement.

see:
https://mbworld.org/forums/e-class-w...my03-06-a.html

@ GNMA: I'll take my chances, especially after considering the possible life saving effect of the better performance and conveniece (SBC stop and SBC -hold)! I think the bad press is completely over dramatised. Apart from the stigma (which you help enforce - it seems to be most prominent in the US?) MB had to come up with a work around. If you read their article on the cancellation of the break-by-wire technology then it is clearly stated that it the conventional system is a great cost saving for MB. I think this was the main driver as the merger with Chrystler resulted in active cost saving plans. Also consider that the Maybach and other low volume high-end MB vehicles retains the SBC to their repsective life cycle ends.....therefore the system had good enough integrity to be continued to be use in these lines.

Do you still fly in an aircraft after considering how many of them had failures in mid air with catastrophic effect? Do you limit travel by chosing only the more reliable between Boeing or Airbus?

gaazmon

Ya, I haven't heard of any problems on the 06 models.

Hubi

Yeah, thats what I think to - they wanted to cut their costs, nothing else.

So, did you have the same problem with the vibration? does it mean that something is broken? or this improvement is just to get rid of it?

Ronaldk

@ Hubi, I did not have a vibration problem with the SBC breaks. I did notice that if your foot was on the pedal and the system was increasing pressure one could feel 'n slight vibration (subtle) during the process. This will happen (depending on breaking use) approximetly once or twice during a short trip. This was obviously not there if the pump was not building up pressure. After replacement of the suction one can hardly feel any pump vibration (during it's operation) and it has become significantly more quiet.

Hubi

SAME WITH MY CAR. I 'VE TO GO TO THE SERVICE AND ASK THEM TO FIX IT. DON'T HAVE A WARRANTY AND RECALL IS PROBABLY DONE AND NO LONGER AVAILABLE, SO PROBABLY WILL COST A LOT, ANYWAY

THANKS

edwinwalke

If your problem is the SBC pump it has a warranty the is for 10 years and unlimited mileage. Recalls do not expire, especially safety related so I would take it to the dealer and get their input and if they want to charge get a detail estimate and then bounce that off MBUSA.

Hubi

thanks, i didn't know about 10y warranty...and recalls without the expiration date. How can we check by VIN (means where) if our car was qualified for recall? I got it from the first owner but I don't really know if they fixed it

hubi