Outstanding. 🥇 That’s a pretty far cry from the ones around here listed for $7k-$9k USD. If we had an ‘05 it would have 400,000 miles on it. We’ve never been able to have one that we set aside for special occasions and give love to. I think I would bite the bullet and fix it too.

 

Just to set things straight on the reply who says it’s Bs that you loose braking power.

My alternator went and I was limping the car home and then to the garage. I was living in the Swiss alps at the time so all the hills there are very steep. Coming down the hill from my apartment I found that the battery power had dropped so I had no SBC and was on the emergency circuit only.

I was effectively a passenger with only steering once the brake power went, I managed to stop when I got to the flat but I could not stop on the downhill section.

Thats my experience of SBC not working.

 

Update. My car is fixed. Total repair cost was around $2,000.00. Found a reman unit for a lot less than Mercedes wanted.

R.K.

 

Hello. Nice upthread description of SBC failure. The sparring was fun to read too.

Anyhow, my 2005 e500 has check engine CAN errors that flash when depressing the brake HARD. I've a service brake warning too from a stop light voltage check dtc since purchase though no SBC fail has been experienced. Erasing the stored dtc's removes the check engine light and no brake problems are notable.

Q: What is necessary for a dealership to activate the SBC warranty? Must the vehicle experience catastrophic failure before SBC warranty activates?

ATM there's no explicit SBC fail. Professionally serviced the ECU, EIS for any defects. None noted. Swapped the instrument cluster with no effect on the CAN issues. SAM replaced, no effect. Replaced stop light switch, no effect. Distribution blocks are clean and serviceable. 60 ohm readings at rocker panel distribution block. Thanks for reading and considering this all.

The below dtc's arise only after parked HARD brake depression:

 

The stored codes all look like low voltage/battery replacement type of thing that should be cleared. The 930E code I have never seen, but a quick search does give others that have seen it with no resolution. To answer the question without an actual SBC scan via Star - you simply don't know.. I would suggest taking the car to MB, have them run a star scan check and let you know if anything is covered. If not, they may hit you up for an hour of labor for the scan ($200+ in many areas) even thou the tech will really only spend at most 15 mins doing this....

 

Ok! Thank you.

The SBC unit has a 5 second mechanical rattle when activated. Is the atypical? Has anyone experienced this? Here's a video of the rattle:

https://www.dropbox.com/scl/fi/dlqn8...=66i8wg2p&dl=0

 

The SBC computer activates in a number of conditions, opening the driver door is one of them.

 

It’s louder and more metallic than I remember, but that might be the pump. If the accumulator is low on pressure, the pump will come on to bring it back up. SBC sets the brakes in a number of conditions as a safety measure.

 

More info about SBC: https://www.yumpu.com/en/document/re...ke-control-sbc

 

Recently I had a scary experience. When I trying to stop, the brake warning light flashed and I had reduced braking power. I found the extended warranty for the SBC unit on this forum and brought my 2005 e320 to the Mercedes Benz Service Center. After some back and forth, they stated that the brake light switch was the probable cause and replaced it under the extended warranty.

My question: Can a faulty brake light switch cause a loss of braking power? I'm concerned that the SBC unit should have been replaced and brought this to the service advisor attention. However, the service advisor/tech stated that this should fix the issue. What should my next steps be?

 

"However, the service advisor/tech stated that this should fix the issue."

Did the service remove the warning light?

The brake light switch is a $10 part. I've replaced the stop lamp switch x3 and the test voltage brake warning dtc returns soon after. The stop lamp dtc will change from active to stored after enough time it'll will reoccur.

In my experience, without active SBC failure there's not much proof to justify a SBC warranty activation. Without running a detailed scan there's little to go on and dealers are not too specific...i.e. they keep you in the dark...leaving you with a lot of wondering if you are in imminent danger.

Spare yourself a lot of wondering and buy a YOUCANIC multivehicle scanner. I did last year after I realized as a noob I was in over my head and dealer charges would have racked up into the +$10000 for stuff that can be addressed in your garage with a few trips to Harbor Freight for specialty sockets and such or an independent shop for a lot less...if you simply know what you are dealing with to guide the servicing. The scanner allows manipulation/disactivation of the SBC brake system, live data of all vehicle modules too. For your peace of mind either sell the car or get the scanner. My vehicle flashes warnings for any wobbly voltage or delayed air reservoir tank filling though wouldn't know what was going on without my scanner, only that the brakes and suspension need servicing.. You'll spare yourself all the back and forth and soon will be seeing what the tech sees and give yourself time to think reasonably how to proceed.

It was distressing initially to be under the car often fixing transmission leaks and oil level sensors and Airmatics and broken trunk wiring and heater valves and brake system parts and serpentine belts and CAN system errors and rough viscous coupler and after awhile being ok with the vehicle running well with some imperfections and sporadic visit shop suggestions.

I believe the W211 a nice vehicle and has a bulletproof engine though is engineered to report any variance outside of its tight specifications. My Ford is easier to maintain and simpler to dx and such and the scanner helps with dx there too.

Reason I recommend the YOUCANIC is it is a lot cheaper than STAR dx or others and you'll get a OBD2 scanner that works on all models and the company reps will write you back re: queries, simple or complicated. Send scanner output and they'll give a best guess which is better than out of pocket $ and time spent at the shop for a maybe [size=13px]nothing-burger and get you on your way to a good nights sleep and more $ in your pocket than without. Ask me how I know....[/size]

[size=13px]Anyways, with some definitive dx information in hand and you'll like your purchase a lot more too. This website has helped me a lot just sticking with my mess of a car, slowly fixing what I can to keep it safe.[/size]

[size=13px]Oh, change the transmission, front, rear differentials and transfer case fluid soon if you haven't any service records on that. When the fluid fails it fails fast.

My two cents.

Have a great day, ok?[/size]

2005 E500

 

Also check the SBC unit and check for leaks around the "bulb" aka the accumulator. If its leaking or has brake fluid residue around the connection on the SBC, the brake switch wont help.

 

so i got a 05 E320, and whenever i pump the brakes makes a errrrrrr sound, coming from the abs or what mercedes call, sbc, all i got is a abs light on no warnings about "braking reduced" so im wondering is that actually the sbc failing?

 

If I understand correctly, this car is new to you. The sound is probably normal. SBC has a pump to maintain reservoir pressure. And if you’re not getting red warning of brake failure on the instrument cluster, then whatever it is, it’s not severe at this point. That could be triggered by a wheel speed sensor. I suggest scanning with a Mercedes dedicated scanner or one with software specific to your car.