ESP control mode, function - GF42.45-P-3700TX

MODEL 211, 219.3 up to 31.5.06 except CODE (494) USA version except CODE (498) Japan version 

MODEL 211, 219.3 up to 30.6.06 with CODE (494) USA version with CODE (498) Japan version 

Fig 1: ESP Control Mode Function Diagram - Pressure Buildup

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Electronic Stability Program (ESP) closed-loop regulation 

ESP control mode, pressure build-up 

The control process shown in the example and the valve positions refer to the right front wheel brake (FR).

An intervention into the brake system for vehicle stabilization at the right front wheel brake (FR) is introduced by the ESP control unit (N47-5) (FR).

The left front separation valve and right front separation valve and the front axle balance valve are closed at the start of ESP control. The right front outlet control valve remains closed. The right front inlet control valve is open.

The pressure from the pressure reservoir (3) can now be built up at the brake caliper of the right front wheel brake (FR).

Fig 2: ESP Control Mode Function Diagram - Pressure Holding

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

ESP closed-loop operation pressure holding 

The control process shown in the example and the valve positions refer to the right front wheel brake (FR).

If for stabilization no more powerful intervention in the brake system is required, the Electronic Stability Program closed-loop operation "pressure holding" begins.

The right front inlet control valve is closed. As a result the pressure from pressure reservoir (3) cannot be increased in the brake caliper of the right front wheel brake (FR).

Fig 3: ESP Control Mode Function Diagram - Pressure Reduction

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

ESP control mode, pressure reduction 

The control process shown in the example and the valve positions refer to the right front wheel brake (FR).

If the brake pressure required for stabilization is too high, the Electronic Stability Program closed-loop operation "depressurization" starts.

The pressure reduction phase is introduced by opening the right front outlet control valve. The right front inlet control valve and front axle balance valve remain closed.

The returning brake fluid flows via the return pipe to the brake fluid reservoir.