Component Description For Electronic Stability Program Control Unit - GF42.45-P-5119RF

Model 205 (except 205.012/013/047/053/054/147/212/213/247/253), 253 (except 253.354/954/99) 

Shown on model 205.0 

Location 

The Electronic Stability Program control unit is located in the engine compartment, at the left next to the BAS brake booster (A7/7) at the traction system hydraulic unit.

Tasks 

The Electronic Stability Program control unit controls the following functions:

• Electronic Stability Program (ESP®)
• Electronic brake force distribution (EBD)
• Anti-lock braking system (ABS)
• Acceleration skid control (ASR), electronic traction system
• Brake Assist System (BAS)
• Brake Assist System PLUS (BAS PLUS) (with CODE 23P (Driving assistance package))
• Hill Start Assist
• Downhill Speed Regulation (DSR) (model 253 with code 430 (Offroad package))
• Flashing adaptive brake lights
• Dry braking
• Precharging, depending on accelerator pedal actuation
• Precharging, depending on lateral acceleration
• HOLD function
• ESP® trailer stabilization (with CODE 550 (Trailer hitch))
• PRE-SAFE® system (with CODE 23P (Driving assistance package))
• Standstill control (SSC)
• Steer Assist
• Crosswind Assist
• Tire pressure loss warning (TPM) (except CODE 475 (Tire pressure monitor))
• Permanent Speed Limiter (except for code 23P (Driving Assistance Package) and except for code 494 (USA version))
• Variable speed limiter (Speedtronic) (except CODE 23P (Driving assistance package))
• Electric parking brake (EFB)

The variable speed limiter and permanent speed limiter functions are integrated in the radar sensors control unit (N62/1).

The Electronic Stability Program control unit has the following tasks:

• Reading in of signals 
• Evaluation of input factors 
• Actuation of components 

Reading in of signals 

The input factors are read in via the following connections:

• Direct line 
• Suspension FlexRay (Flex E) 
• Vehicle dynamics CAN (CAN H) 

Direct line 

The Electronic Stability Program control unit reads in the signals from the following components over direct lines:

• Brake vacuum sensor (B64/1)
• Traction system hydraulic unit
• Left front axle rpm sensor (L6/1)
• Right front axle rpm sensor (L6/2)
• Left rear axle rpm sensor (L6/3)
• Right rear axle rpm sensor (L6/4)
• Brake lights switch (S9/1)
• Electric parking brake switch status (S76/15) (except model 205.086/087/286/287/386/387/486/487 and model 253.364/388/389/964/988/989)

Chassis FlexRay 

The Electronic Stability Program control unit is a chassis-FlexRay user.

The following signals, for example, are read in via chassis FlexRay:

• Signals from instrument cluster (A1)
• Signals from radar sensors control unit (with code 23P (Driving Assistance Package))
• Status of circuit 15 of the electronic ignition lock control unit (N73)
• Status of trunk lid/liftgate buckle (A85/5) from rear SAM control unit (N10/8)
• Status of left front door rotary tumbler switch (A85s1) from left front door control unit (N69/1)
• Currently engaged gear range from fully integrated transmission control unit (Y3/8n4)
• Status of drive train operational, engine running and accelerator pedal position from ME-SFI [ME] control unit (N3/10) (gasoline engine) or CDI control unit (N3/9) (diesel engine)
• Status of On/Offroad menu button (S70s1) and status of Downhill Speed Regulation button (S70s2) (model 253 with code 430 (Offroad package)) from Audio/COMAND control panel (A40/9)

Vehicle dynamics CAN 

The Electronic Stability Program control unit is a dynamics CAN user.

The following signals are read in over the dynamics CAN:

• Status of driver seat belt buckle switch (S68/3) from Supplemental Restraint System control unit (N2/10)
• Vehicle sprung mass vibrations from the Supplemental Restraint System control unit

Evaluation of input factors 

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Actuation of components 

Components are actuated with the following line:

• Direct line (except model 205.086/087/286/287/386/387/486/487 and model 253.364/388/389/964/988/989) 
• Chassis FlexRay 

Direct line (except model 205.086/087/286/287/386/387/486/487 and model 253.364/388/389/964/988/989) 

The Electronic Stability Program control unit actuates the following components over direct lines:

• Traction system hydraulic unit
• Left electric parking brake actuator motor (M76/1)
• Right electric parking brake actuator motor (M76/2)

Chassis FlexRay 

The Electronic Stability Program control units sends, for example, the following requests and status messages over the chassis FlexRay to the corresponding control units:

• Request to display messages and warnings to the instrument cluster.
• Status of service brake to front SAM control unit (N10/6)

Wiring diagram for Adaptive Brake (ABR)

PE42.47-P-2000-97FBA