If you have a Mercedes Benz with  Sensotronic Brakes, also known as a brake by wire, you may have been greeted with the “Brakes Defective Stop Vehicle” error message in your instrument cluster. Three common types of failures happen with the Drive-by-Wire brakes on the Mercedes Benz.

1. The operating time of Component A7/3 is exceeded.
2. Complete failure of the SBC/Electro-Hydraulic Brake System Hydraulic Pump
3. A defective brake switch could cause the same error message in a few cases. You can buy one on Amazon for less than $20. The switch is above the brake pedal and can easily be replaced by anyone.
   

Based on their testing and research, we believe that Mercedes Benz set a cycle limit to the SBC Hydraulic pump. The SBC module counts breaking cycles; after exiting the value of approx 300000, an error message occurs. Some of the errors reported are:

• SBC Control module failure
• STOP VEHICLE  displayed on the instrument cluster
• Brake defective stop vehicle
• REDUCED BRAKING POWER – VISIT WORKSHOP (Replace brake light switch first.)

Your SBC pump is defective, and you lose all the braking or have reduced braking power. The SBC pump, which creates pressure and applies that pressure to the brakes when you push the brake pedal, is not working correctly. This error is standard on Mercedes E Class W211, SL R230, and CLS Class with  SBC Error CODE C249F. After so many operation cycles, the SBC loses efficiency or can fail while driving. So that you don’t get a failure while driving, they want you to replace the SBC Hydraulic Unit before it fails catastrophically.

Understanding SBC (drive-by-wire) brakes.

Here is a great pdf document hosted on the Mercedes Benz forum that explains how the SBC brakes work. Mercedes-Benz publishes this. Or read this article from the 500sec.com website.

Get a new SBC Pump installed for free by the dealer.

The dealer has extended the warranty of the SBC to 10 years and unlimited miles. It doesn’t matter how many owners the car has had or if you have an existing warranty. If you have a Mercedes-Benz with this problem and the car is less than 10 years old, find a local Mercedes-Benz dealer and take the car to be repaired. Enter your zip here to find the dealer nearest to you. They will tell you that they need to diagnose it first. Let them do that, as they have to send a request for repair to MBUSA and get approval.

Here is a copy of the Warranty Coverage Extension (SBC/Electro-Hydraulic Brake System Hydraulic Pump) Mercedes Benz issued.

How to disable the “Brake Defective Stop Vehicle” Warning.

Reset the operation time/cycle of the SBC Hydraulic Pump.

 

It is possible to reset the SBC Hydraulic Pump using Star Diagnostics. Please be aware that if you do this, you could lose the brakes while driving, which could cause serious injuries or death. Here are the instructions. 

Use at your own risk.

RESET SBC SERVICE LIGHT:
1st: make sure that engine is running!!! In SD Developer mode, you need to go to:
Entwickelingsdaten (developer data) —> ansteueringen (control gear) —> Gesamstliste aller Ansteuerungen (complete list of all the control circuits).

See how many times the brake has been pressed.  
Bremsenzahler (DJ_GetBrLive) (brake payer (dj_getbrlive)). 

Then below you see:
Bremsenzahler aktualisieren und Lebensdauerzahler F neu berechenen (brake upgrade and lifetime payer payers recalculated f) -> click it ! Parameter uINBR = 0 then click F3 

1 line down you see (or search for this line):
Bremsenzahler auf beliebigen Wert setzen (DJ_SetNBr) -> click it Parameter uINBR = 0 then click F3 

Then scroll down until you see the line’s: 

Lebensdauerzahler F neu berechenen (DJ_CalcLiveTime) Parameter uINBR = 0 then click F3 

Lebensdauerzahler F neu berechenen und schreiben (DJ_BuildAndWriteF) Parameter uINBR = 0 then click F3 

Log out of SBC !! Log out of vehicle!! 

 

Potentially catastrophic!

 

Impacted Bosch Part Numbers:

• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 012 (0265960012)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 013 (0265960013)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 015 (0265960015)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 018 (0265960018)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 019 (0265960019)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 020 (0265960020)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 023 (0265960023)
• Mercedes E Class W211/R230 SBC Repair CODE C249F – 0 265 960 025 (0265960025)

 

SBC Hydraulic Pump Error Codes

SBC – MB Number 0044314212 HW Version 11.2002 SW Version 17.2004
Code
C25D6 This fault can be ignored and erased
C26DE Hydraulic fault: Malfunction in pressure supply
C26BB Hydraulic fault: Malfunction in pressure supply

ESP Error Code
C14BE System faults: Test control module A7/3n1 (SBC control module)

 

How to Reset SBC Malfunction

 

What Scanner Can I Use to Troubleshoot Mercedes-Benz Problems?

If you’re experiencing problems with your Mercedes-Benz, the YOUCANIC full system diagnostic scanner can provide invaluable assistance in troubleshooting the issues. By connecting to your car’s onboard computer, the scanner can read fault codes and provide detailed information about any problems with your engine, transmission, brakes, and other systems. Additionally, the scanner can perform diagnostic tests on various systems, such as the ABS, airbag, and steering systems, to help identify the underlying cause of any issues.

In addition to providing diagnostic information, the YOUCANIC scanner can save you time and money on repairs by enabling you to perform simple fixes yourself. For example, if you notice the check engine light on, the scanner can assist you in identifying the problem and determining if it’s a simple issue you can address at home or if you need to take it to a mechanic. This can help you avoid unnecessary trips to the repair shop, saving you both time and money.

Overall, the YOUCANIC full system diagnostic scanner is a powerful tool to help you maintain and troubleshoot your Mercedes-Benz. It’s an excellent investment for both DIY mechanics and professional technicians, as it can assist in diagnosing and resolving even the most complex automotive problems easily, saving you time and money on costly repairs.