ASC control mode, function - GF42.45-P-3500D

MODEL 163 as of 1.9.02 with CODE (472) Electronic Stability Program (ESP) 

MODEL 170 with ENGINE 111,112 with CODE (472) Electronic Stability Program (ESP) 

MODEL 202 with ENGINE 111, 605, 611 with CODE (472) Electronic Stability Program (ESP) 

MODEL 203 with CODE (472) Electronic Stability Program (ESP) 

MODEL 208 with ENGINE 111 with CODE (472) Electronic Stability Program (ESP) 

MODEL 209 with CODE (472) Electronic Stability Program (ESP) 

Shown using model 209 as an example 

ASR control mode - build up pressure 

The control procedure and value positions illustrated in the example refer to the RR  brake.

If one of the drive wheels begins to spin when the vehicle is starting off or accelerating, the ESP control unit initiates the ASR pressure build-up control mode.

At the start of the ASR control the rear axle switchover solenoid valve (y19) is switched into the "Lock position" (closed) and the high-pressure and return pump (m1) is actuated.

The rear axle inlet solenoid valve (y23) is only opened during the pressure buildup phases. In the process the rear axle pump (p2) draws brake fluid out of the reservoir (y23) via the rear axle inlet solenoid valve and via the master brake cylinder.

The pressure limiting valve integrated in the rear axle switchover solenoid valve (y19) serves high pressure limitation (min. 150 bar).

Shown using model 209 as an example 

ASR control mode - hold pressure 

The control procedure and value positions illustrated in the example refer to the RR  brake.

The hold pressure ASR control mode begins when strong brake intervention is no longer required to prevent drive slip.

The rear axle inlet solenoid valve (y23) and right rear solenoid valve (pressure hold) (y12) are closed. As a result the pressure in the brake caliper cannot be increased via the rear axle pump (p2).

Shown using model 209 as an example 

ASR control mode - reduce pressure 

The control procedure and value positions illustrated in the example refer to the RR  brake.

The pressure reduction ASR control mode begins if the braking pressure required to prevent drive slip is too high. The pressure reduction phase is introduced by opening the right rear solenoid valve (pressure release) (y13). The right rear solenoid valve (pressure hold) (y12) remains closed.

The brake fluid flowing back returns to the brake fluid reservoir via the rear axle pump (p2) through the pressure limiting valve integrated in the rear axle switchover solenoid valve (y19) via the master brake cylinder.

The rear axle pump (p2) is actuated pulsed during all control phases (depending on the requirement).

Different damping components (12, 13, 14) are installed to further reduce noise levels.

	ESP control unit, location/task/function	Model 163 Applicable as of 9/02	GF42.45-P-4500M
		Model 170, 202, 208 Model 203 up to 7/01	GF42.45-P-4500C
		Model 203 from 8/01 Model 209	GF42.45-P-4500T
	Traction systems hydraulic unit, location/task/ design/function		GF42.50-P-4000D