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Home >> Volvo >> 2007 >> S40 Base, 2.4 39, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Miscellaneous - Design And Function (544 Body) >> Electrical Power Steering Module (EPS) (2004-2010) >> System Overview >> Electro Hydraulic Power Steering
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Electro Hydraulic Power Steering

Fig 1: Identifying Electro Hydraulic Power Steering System Overview
GLL128741Courtesy of VOLVO CARS OF NORTH AMERICA.

The power steering system is electro hydraulic and governed by the electrical power steering module (EPS). The control module regulates the power steering assistance based on input signals. This allows it to provide optimal steering assistance, irrespective of whether the vehicle is stationary with the engine running or is being driven at high speed. The functions managed by the electrical power steering module (EPS) are active when the engine is running.

The control module is under the right-hand headlamp. The control module and pump motor make up a single replaceable unit.

The electrical power steering module (EPS) is powered by the battery (30 supply) via a fuse in the integrated relay/fusebox in the engine compartment. The electrical power steering module (EPS) receives a 15 supply via the ignition switch and is unfused in the integrated relay/fusebox in the engine compartment and in the central electronic module (CEM). The electrical power steering module (EPS) is grounded in the left-hand suspension turret via a ground lead.

The electrical power steering module (EPS) communicates with other control modules using controller area network (CAN) communication.

If replacing the electrical power steering module (EPS), software optimized for the profile of the car must be downloaded into the control module. If this is not done, although the power steering will function, it will not be optimized to the profile of the car.