Frequently Asked Questions

SBC (Sensotronic Brake Control) is Mercedes' brake-by-wire system by Bosch, used in E-Class W211/S211, CLS C219, and SL R230 models. Unlike conventional brakes where your foot pressure directly operates the brakes, SBC uses sensors to detect your braking intention and an electrohydraulic pump to apply the brakes.

The system tracks braking operations, pump RPM and fluid service intervals to estimate pump life. When thresholds are reached (approximately 300,000 brake actuations), it logs fault code C249F, shows "Service brake! Visit workshop!" on your dashboard, and switches to emergency/backup mode.

Beyond the counter limit, pumps can also fail due to:

• Motor brush wear (the electric motor brushes wear down over time)
• Hydraulic valve degradation
• Seal failures causing pressure loss
• Accumulator failure (soft accumulator - code C2131)
• Electronic control unit faults

Our SBC repair services are priced as follows:

• Counter Reset Only: £120 (software reset only, no hardware repair, no warranty)
• Full Pump Rebuild (by post): £410 (includes 6-month warranty)
• Replacement Pump: From £500 (depends on your SBC part number)
• Mobile Service: £650 fixed price (includes 12-month warranty)

Compare this to dealer replacement costs of £2,500-£3,000+. And here's a fact most people don't know: Bosch stopped manufacturing new SBC pumps in 2012. This means even "new" units from dealers are actually refurbished — just like ours, but at 5x the price.

All rebuilds include full hydraulic testing on our professional bench rig before return.

Yes! We offer complete mobile SBC repair within approximately 200 miles of Basingstoke, including London and surrounding areas.

What's included in our mobile service (£650):

• Professional diagnosis of SBC faults
• On-site removal & refit of your SBC pump
• Repair/rebuild or exchange (as required)
• Software update, coding & safe lifetime counter reset
• Brake fluid change & full system bleed
• Initialization, road-test & report
• 12-month warranty on our work

The complete job takes approximately 2-4 hours on-site. You'll need a safe, level space to work (driveway or garage) with the vehicle accessible, keys available, and battery charged.

Travel surcharge may apply for distant locations — please message us with your postcode for availability and exact pricing.

⚠️ Reset-only is NOT recommended and has NO warranty.

Clearing the lifetime counter without addressing hydraulic/mechanical wear is unsafe. The counter exists for a reason — it tracks component wear. Simply resetting it without inspection or repair means you could have worn hydraulic components, failing seals, or degraded valves that will continue to deteriorate.

Our proper rebuild process:

1. Disassemble and inspect your SBC unit (A7/3)
2. Replace worn hydraulic components
3. Bench test for correct pressure and CAN communication
4. Reset the lifetime counter after confirming hardware is good

We offer reset-only (£120) for customers who specifically request it, but we do not recommend it as a standalone fix for safety-critical brake hydraulics, and it comes with no warranty.

SBC (Sensotronic Brake Control) was fitted to the following Mercedes models:

• W211/S211 E-Class: 2002-2006 (pre-facelift only)
• R230 SL: 2001-2011 (all years)
• C219 CLS: 2004-2010
• C215 CL-Class: 1999-2006

Important: The W211 facelift models (2006 onwards) returned to conventional brakes after reliability concerns. If you're unsure whether your car has SBC, look for the "SBC" badge on the brake fluid reservoir cap or check for the distinctive SBC pump unit near the front left wheel arch.

You can also check your part number against our supported part numbers list.

It depends on the warning colour:

Grey/White "Service Brake Visit Workshop":
The car enters backup mode with reduced braking capability. Only the front brakes work via a conventional hydraulic backup, and you'll notice the pedal feels different (harder, longer travel). You can drive carefully to a safe location, but don't drive far. Braking distances are significantly increased. Arrange repair urgently.

RED Brake Warning:
STOP IMMEDIATELY. This indicates a serious fault that has compromised the braking system. Do not attempt to drive. Pull over safely and arrange vehicle recovery to a workshop.

Even in backup mode, we recommend getting the vehicle recovered rather than driving any significant distance. Your safety is paramount.

Common SBC-related fault codes include:

• C249F: Lifetime counter exceeded (most common)
• C2498: High-pressure reserve depleted / lifetime service message
• C2131: Soft accumulator (preload pressure below spec)
• C217B: Valve relay power supply fault
• C223C: Front-left inlet control valve fault
• C22BD / C223D / C233D / C23BD: Pressure increase faults (individual wheels)
• C226F / C22EF / C254F / C258F: Internal control unit errors
• C235A - C235E: Wear detection / pressure regulation faults
• C25D4 / C26BB / C26BE / C26F5: Pressure supply / hydraulic errors

For a complete list with detailed explanations, see our SBC Fault Codes page.

If you have diagnostic equipment that can read these codes, please share them when contacting us — it helps us diagnose the issue before you send the pump.

Turnaround times depend on the service:

• Posted Pump (rebuild): 24-48 hours once we receive it
• Mobile Service: 2-4 hours on-site, by appointment
• Workshop Service (bring your car): Often same-day
• Counter Reset Only: Usually same-day

We test every pump extensively on our professional bench rig — checking pressure output and CAN communication — before returning it. This ensures your pump works correctly before you go through the hassle of refitting.

No — this is one of the key advantages of our service.

Because we repair YOUR original pump (rather than replacing it with a different unit), all the vehicle-specific coding is preserved. The pump already knows your car's VIN and configuration.

After refitting a rebuilt pump, you may need to:

• Bleed the brake system properly (requires diagnostic tool)
• Clear any stored fault codes
• Perform a steering angle sensor calibration (if prompted)

If you choose our mobile service or bring the car to us, we handle all of this for you.

Our warranty terms depend on the service:

• Counter Reset Only: No warranty (software only, no hardware repair)
• Full Rebuild (by post): 6-month warranty
• Replacement Pump: 6-month warranty (can upgrade to 12 months)
• Mobile Service / Full On-Car Service: 12-month warranty

The warranty covers:

• All parts we replace (hydraulic components, seals, valves)
• Counter reset (won't return prematurely)
• Workmanship

We've completed 767+ SBC repairs with 100% positive feedback on eBay. Our track record speaks for itself.

Yes, if you're mechanically competent. The pump is located in the front left wheel arch area. The basic process is:

1. Depressurise the system (important for safety)
2. Remove the wheel arch liner
3. Disconnect electrical connectors
4. Mark and disconnect brake lines
5. Unbolt the pump unit
6. Remove the mounting bracket to avoid transit damage

Packaging for shipping:

• Close/cap hydraulic ports to prevent contamination
• Wrap the block in cloth and seal in a plastic bag (brake fluid may leak)
• Put your details/order number in a separate sleeve
• Use tracked/insured shipping

Important: When refitting, the system must be bled properly — this typically requires a diagnostic tool to activate the pump during bleeding.

If this sounds complicated, choose our mobile service and we'll handle everything.

Your SBC part number is printed on a label on the unit itself. It typically starts with:

• Mercedes numbers: A004..., A005..., A006..., A008..., A009..., A199..., A240...
• Bosch numbers: 0265..., 0986...

You can check if we support your unit on our Part Numbers page. If yours isn't listed, message us anyway — we likely support it.