Electric Parking Brake Release, Basic Function - GF42.20-P-1004A

Model All (4xWD, CAR) 

Overview 

This document contains information on:

• General 
• Function requirements 
  • Additional function requirements for the automatic release of the electric parking brake (EFB) (automatic transmission) 
  • Additional function requirements for the automatic release of the electric parking brake (EFB) (manual transmission) 
  • Additional function requirements for automatic release of electric parking brake (EFB) (electric vehicle) 
• Function 
  • Manual release of electric parking brake (EFB) 
  • Automatic release of electric parking brake (Comfort Go) 

General 

The EFB is released either manually via the electric parking brake switch or automatically according to the driving state.

Function requirements 

• Ignition ON (circuit 15)
• Trunk lid is closed if transmission is in position "R"

Additional function requirements for the automatic release of the electric parking brake (EFB) (automatic transmission) 

• Engine in operation
• Seat belt tongue is inserted into driver seat belt buckle
• DIRECT SELECT selector lever position D or R and accelerator pedal operated

Additional function requirements for the automatic release of the electric parking brake (EFB) (manual transmission) 

• Engine in operation
• Driver door closed
• Gear engaged and accelerator pedal depressed

Additional function requirements for automatic release of electric parking brake (EFB) (electric vehicle) 

• Drive system in operation
• Seat belt tongue is inserted into driver seat belt buckle
• Driver door closed
• DIRECT SELECT selector lever position D or R and accelerator pedal operated

Function 

Manual release of electric parking brake (EFB) 

The parking brake release is requested by actuating the electric parking brake switch. The ESP® control unit actuates the left and right electric parking brake actuator motors and releases the electric parking brake (EFB) completely. A signal for the parking brake indicator lamp (red) is generated. The parking brake indicator lamp (red) in the instrument cluster goes out.

The EFB is released automatically as soon as there is a sufficiently high drive torque at the drive wheels to enable the vehicle to drive off. The ESP® control unit actuates the electric parking brake actuator motors and releases the electric parking brake (EFB). If a fault prevents the EFB from being released, the instrument cluster displays the message "Release parking brake" and a warning tone is sounded.

Automatic release of electric parking brake (Comfort Go) 

	Additional basic functions
	Electric parking brake actuator motors, basic function		GF42.20-P-2000A
	Electric parking brake switch, basic function		GF42.20-P-2004A