GF07.61-P-4018MIK ME Power Steering Pump Pressure Regulator Valve Actuation Function

GF07.61-P-4018MIK ME Power Steering Pump Pressure Regulator Valve Actuation Function
- refinement package
- as of model year 09


Function requirements for actuation of power steering pump pressure regulator valve (Y10/1) - general
^ Circuit 87M ON (engine control ON)
^ Engine running

Actuation of power steering pump pressure regulator valve - general
The power steering pump pressure regulator valve regulates the assisted steering pressure according to the requirements. By actuating the power steering pump pressure regulator valve according to requirements, engine load is lowered and fuel consumption is therefore reduced.

To actuate the power steering pump pressure regulator valve, the ME-SFI control unit (N3/10) reads the following sensors and signals:
- Crankshaft Hall sensor (B70), motor speed
- ESP and BAS control unit (N47-5), vehicle speed over the engine compartment CAN (CAN C)
- Steering column tube module (N80), rate of change of steering angle (calculated from steering angle variation) and steering angle over the engine compartment CAN

Actuation of power steering pump pressure regulator valve, function sequence
The power steering pump pressure regulator valve is actuated according to a performance map by the ME-SFI control unit, using a PWM signal with a duty cycle of 10 to 90 %.

The power steering pump pressure regulator valve is located in a bypass to the work chamber of the power steering pump.
Depending on the PWM signal, the power steering pump pressure regulator valve varies the opening of the bypass, and so regulates the flow rate in the power steering pump according to the requirements.

With ignition ON and during engine start, the power steering pump pressure regulator valve is not actuated (bypass open). Maximum steering assistance power is then available through the power steering pump.