Electric Parking Brake Control Unit, Component Description - GF42.20-P-5005RDA

Model 172.4 

as of Model year 2017 

Viewed from rear 

Location 

The electric parking Brake control unit is on the right on the control unit carrier in the luggage compartment.

Tasks 

The electric parking Brake 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 over the following connections:

• Direct line 
• Chassis CAN 1 (CAN E1) 

Direct line 

The signals from the following component are read in via direct lines:

• Status of the electric parking Brake switch (S76/15)

Chassis CAN 1 

The following information is read in over chassis CAN 1:

• "Circuit 15R ON" status, from the electronic ignition lock control unit (N73)
• Status of driver seat belt buckle restraint system switch (S68/3), from the supplemental restraint system control unit (N2/10)
• Status of the trunk lid rotary tumbler switch (M14/7s1), from the front SAM control unit with fuse and relay module (N101), which receives the status from the rear SAM control unit with fuse and relay module (N10/2) via the interior CAN (CAN B).
• Road gradient, from the Electronic Stability Program control unit (N30/4), which receives the signal from the turn rate, lateral acceleration and longitudinal acceleration sensor (B24/15) (with code 239 (DISTRONIC PLUS)) via the vehicle dynamics CAN (CAN H), or directly determined by the Electronic Stability Program control unit (except code 239 (DISTRONIC PLUS)).
• Wheel speeds and enable signal by the Electronic Stability Program control unit
• Selector lever position from the DIRECT SELECT INTERFACE (N150), circuit 61 ON status and accelerator pedal position from the CDI control unit (N3/9) (with diesel engine) or ME-SFI control unit (N3/10) (with gasoline engine)

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 

The actuation of the components takes place via the following connections:

• Direct line 
• Chassis CAN 1 

Direct line 

The electric parking Brake control unit actuates the left electric parking Brake actuator motor (M76/1) and the right electric parking Brake actuator motor (M76/2) via a direct line.

Chassis CAN 1 

The following components are actuated via chassis CAN 1:

• Instrument cluster (A1) (output of messages and warnings) via chassis CAN 1 and chassis CAN 2 (CAN E2) with the interface for front SAM control unit with fuse and relay module
• Electronic Stability Program control unit (initiation of emergency braking)

Wiring diagram for electric parking Brake control unit

PE42.20-P-2101-97TAA