danmm7

My 2003 SL55 has close to 137k miles. I've had the car for about a year.
The SBC/Brakes seem to work well. The SBC unit under the hood appears to be the original that came with the car.

I am aware that Mercedes extended the warranty on the SBC for 25 yrs.
I am also reading a lot of discussion about failing SBC units and how the "failure" is usually related to a certain threshold of brake cycles being done and then the system shows a red warning light.
As many of you here already may know, before the warranty extension, servicing and replacing the SBC control unit after such warning was a very expensive adventure and as a result, many people have used a cheap "reset device" to reset the SBC counter and eliminate the service warning.
The reset takes care of the warning by changing a software parameter, but unfortunately the SBC module/pump is still the same from a mechanical/wear point of view. It's still old and still used more times than what Mercedes determined to be safe/optimal.

The SBC is my car is the original unit. The previous owner has no recollection of the SBC ever being replaced or reset ... and we have no visibility IF any of the owners before that have done anything.

At 137k miles and all these years, i wonder if it's normal for my SBC to still function error free?
Or was it reset by someone in the past?!?

Is there a way for me to check if there was ever a reset performed to it? I have a STAR clone.

Rudeney

Keep in mind that the SBC "counter" is not based on brake pedal presses, but on its pump motor cycles. If those are a lot of highway miles where the brakes were not used much, it's certainly possible that the original SBC pump motor has not reached its cycle count yet.

mikefamig

I remember getting a yellow warning about my brakes when I first got the car but I don't remember what it said. I do remember that I found a way to make the error go away but again I don't remember what I did,

Can anyone explain this problem to me? My brakes have always worked normally so I'm not concerned much but I would like to know what this is all about.

Mike.

alk247

I'll try. Mercedes determined that SBS pump can reliably work over a certain number of cycles. There is a cycle counter somewhere in one of the car's computers. TS is concerned, that his car counter was reset sometime in the past, so his pump may be over the cycle limit and may fail soon. He is looking for a way to determine if such reset did take place. I believe that he is afraid to get stranded if SBS pump fails on him without warning. I personally, is not worried about such thing. If it happens, I'd limp to the nearest Benz dealer to get pump replaced under extended warranty. But I do not take my SL on long trips and there are at least four Benz dealers within 50 miles radius form me. YMMV.

mikefamig

Geez I think that I may have reset mine. It was when I first got the car years ago and I'm sure that there was a yellow warning in the gauge cluster concerning the brakes and I did something to make it go away but I don't remember what I did. I think that it was some procedure that I found in the owner manual because i did it while sitting in a parking lot.

Mike.

mikefamig

I looked at the owner manual and it says that the yellow warning indicator comes on when the ABS/ESP system has a problem or the EPS is switched off. Maybe it was just that.

Mike.

Rudeney

You can't reset the SBC cycle by doing anything outlines in the owner's manual. It requires hooking up to SDS to do that.

danmm7

So after some research and lots of reading on various MB forums i found a way to find the current SBC pump actuations count using my STAR scanner.

My current count is at 372,263
Based on my research, the red warning light comes on around 398k.

Based on the above numbers, i am pretty sure my SBC was never reset and i am getting close to the 'special event'.
The good new is, my SBC unit is covered under the 25 yr extended warranty.

For those who have the STAR tool and want to check their SBC status, here is the procedure that i borrowed from another forum post:

Start engine. (Note: If you only are checking the total actuation count and not resetting the count, the engine does not need to be running.)
Start Xentry,
Go through multiple menus to your car's data then select:
Control units
Chassis
SBC Sensotronic brake control
Development data (should be at the bottom of the page)
Actuations
Complete index of Actuations

Break: To only get the count, select “Bremsenzaehler (DF_GetBrLiveTime)”. This gives the total actuations to date.

alk247

Thanks to danmm7 I was able to check my counter - 152336, way to go before warning. One small discrepancy - my SDS line is : DJ_GetBrLiveTime rather than DF_GetBrLiveTime.