Mercedes-Benz W211 - Manuals

5 Advantages of SBC • Improves metering of required brake pressure – each wheel can be precisely controlled • Improved BAS function – monitors release of accelerator pedal and application of brake – maximum pressure available immediately – pre-filling of system (overcoming play) – when the BAS funct...

10 Driving with SBC – Delayed Off Function Time that SBC remains operational after use: • with vehicle stationary and was locked = 20 seconds • with vehicle stationary and ignition in “0”, brake pedal not operated = 2 minutes • with vehicle stationary, ignition in “0”, brake pedal operated in delaye...

11 Warning Display Complete ESP control module failure - Instrument cluster will scroll through failure displays

12 Warning Display SBC control module failure Certain faults will trigger audible signal

13 SBC Components • Brake Operating Unit (BOU) • Wheel speed sensors • Traction System Hydraulic Unit (A7/3)

16 X11/4 Diagnosis Connection X11/4 Pin 9 Z6/33 R230 W211 A7/3n1 SBC N47/5 ESP N15/5 ESM N51/2 ABC X11/4 Pin 9 A7/3n1 SBC N47/5 ESP Z70/4 N10/1 L.F.SAM

18 Brake Operating Unit The Brake Operating Unit (BOU) consists of the following: • Brake fluid reservoir (Do not overfill!) • SBC pedal value sensor • Tandem master cylinder • Brake pressure simulator (Note: no vacuum booster)

19 Master Cylinder • Fluid return line • Supply hose to SBC • Do not overfill • Fluid level sensor • Hydraulic lines to SBC

20 Fluid Reservoir Cover • Ultraviolet protection (211 only)

22 BOU Tandem Master Cylinder Fluid reservoir Floating piston Primary piston Brake pressure simulator Fill valves GF42.46 -P- 4200-03SL A7/3 y1 y2 A7/3 - Traction system hydraulic unit with separation valves y1 and y2

23 Normal Braking - Light Pressure A7/3 y1 y2 GF42.46 -P- 4200-03SL • Driver applies pressure to the brake pedal • Pedal travel sensor sends a signal to A7/3 • Fill valves close • y1 and y2 energized, preventing fluid movement externally • Floating piston allows fluid to enter simulator, compressing...

24 Normal Braking - Increased Pressure A7/3 y1 y2 • Increasing pedal travel causes thelarger spring tocompress, providing harder pedal feel

25 Normal Braking - Strongest Feedback A7/3 y1 y2 • Further pedal travel causes piston to compress rubber bumper, providing greatly increased pedal pressure

26 Emergency Operation A7/3 y1 y2 Left front Right front GF42.46 -P- 4200-03SLGF42.46 -P- 3000SL • All electrical functions canceled • Hydraulic pressure created with NOpower assist • Pressure directed through A7/3 y1 andy2 to .... Left Front andRight Front calipersonly !

28 Traction System Hydraulic Unit A7/3 GF42.50 -P- 4000-03S

29 Legend 1 Brake Operating Unit 2 Brake pressure simulator 3 Pressure reservoir 7 Left front media separator (dividing piston) 8 Right front media separators(dividing piston) A7/3 Traction system hydraulic unit A7/3b1 Front axle pre- pressure sensor A7/3b2 Reservoir pressure sensor A7/3b3 Left fron...

30 Emergency Operation Circuit GF42.46 -P3000SL • Pressure applied directly to front calipers • y1 and y2 not energized • b1, b3, and b4 pressure sensors may provide information to SBC control module • Media separator/Dividing piston 7 and 8 isolateemergency circuit fromnormal circuit

31 Brake Pressure Supply GF 42.50 -P-4000 -04S GF42.46 -P- 0001SL • pressure reservoir charged to 160 bar • the high pressure charge pump runs as needed • pressure blocked by y6, y8, y10, y12

32 Three Pressure Stages Same pressure stages as used with ABS functions: • Pressure apply • Pressure hold • Pressure release

33 Pressure Apply - Rear Wheels GF42.50 -P- 4000-04SGF42.46 -P- 1000SLGF42.46 -P- 4500-02SL Reservoir pressure Brake pedal pressure • Brake pedal depressed• B37/1 and b1 report brake application to control module • y1 and y2 energized• y10 and y12 intake control valves energized • Pressure at each r...

34 Pressure Apply - Front Wheels GF42.50 -P- 4000-04S GF42.46 -P- 1000SL Reservoir pressure Brake pedal pressure • y6 and y8 energized• pressure applied to left and right dividing pistons 7 and 8 • 7 and 8 apply pressure to caliper• pressure at each wheel monitored by b3 and b4 • Balance valve y3 no...

35 Pressure Apply - All Wheels GF42.50 -P- 4000-04S GF42.46 -P- 1000SL • Outlet control valves y7, y9, y11, y13 energized

36 Pressure Hold - All Wheels GF42.50 -P- 4000-04S GF42.46 -P- 1000SL • y6, y8, y10, y12 de-energized

37 Pressure Reduction - All Wheels GF42.50 -P- 4000-04S GF42.46 -P- 1000SL • y7, y9, y11, y13 de-energized

38 Temperature Compensation During continuous brake use the fluid in the calipers expand, this:• creates high pressure • prevents valves 7 & 8 from moving To reduce this pressure, y1 and y2 are pulsed

39 Deactivation Deactivating the system will: • empty the pressure reservoir (a lower pressure with no volume may be retained) • prevent the charge pump from operating •Note: the warning buzzer is deactivated when accessing SBC with the SDS. SBC must be deactivated with SDS before any work is perfor...

42 System Activation Activation must be performed anytime the system has been deactivated, BEFORE the engine is started! Failure to activate will prevent proper operation and create fault codes! Activating SBC with SDS will: • charge the accumulator• perform a Predrive Check• move the pads towards t...

44 Activation - Left Front Caliper held with ~60 bar

45 Activation - Right Front Caliper held with ~60 bar

46 Activation - Right Rear Caliper held with ~60 bar

47 Activation - Left Rear Caliper held with ~60 bar

49 Bleeding the Brake System Proper system bleeding is critical! Follow directions in SDS • Bleeding must be performed using the SDS • Pressure at bleeder valves will exceed 100 bar (Hold the bleeder hose securely) • Bleeding may require ~1.5 hours • Bleeding may use ~ 1.5 liters of brake fluid AR42...

50 Equipment Required • Pressure bleeder• Adapters• Fluid receptacle • SDS - follow instructions carefully CAUTION:Extremely high pressure at bleeder! 211 589 01 91 00 AR42.10 -P- 0010-02RAR42.10 -P- 0012RWS42.00-P- 0048B

51 Bleeding the Brake System AR42.10 -P- 0012R Connect equipment and follow steps in SDS

52 Acronym List (Used in This Handout.) ABS - Anti-lock Brake SystemASR - Anti Slip RegulationBAS - Brake Assist SystemBOU - Brake Operating UnitCAN - Controller Area NetworkEBP - Electronic Brake ProportioningEBR - Electronic Brake RegulationE-Gas - Electronic AcceleratorESP - Electronic Stability ...

53 Appendix AR42.10-P-0010I Carrying out bleeding operation AR42.10-P-0012R Bleeding system with Star Diagnosis GF42.45-P-0001-04SL ESP driver information GF42.45-P-0001SL ESP function GF42.45-P-2000SL ESP brake moment control GF42.45-P-3500SL ASR control mode function GF42.46-P-0001SL SBC function ...