Power steering mechanism (Skoda Fabia 5J)

Contents: Design and method of operation ⬇ Restart protection ⬇ TRW Power Steering Assembly Diagram ⬇ Pressure Line Assembly Diagram - TRW…⬇ Position for pressure line assembly ⬇ Tightening torque ⬇

Design and method of operation

EPHS electrohydraulic power steering (Electrically Powered Hydraulic Steering) - is a power steering mechanism that uses its own electric motor to drive the pump.

1 - Power steering; 2 - Power steering sensor "G250"; 3 - Steering column; 4 - Instrument cluster control unit "J285"; 5 - Speedometer sensor "G22"; 6 - Engine control unit; 7 - Power steering indicator "K92" in the instrument panel; 8 - Signal from the power steering indicator "K92", via CAN-BUS; 9 - Engine shaft speed signal via CAN-BUS; 10 - Vehicle speed signal via CAN-BUS; 11 - Hollow screw with check valve; 12 - Pressure line; 13 - Steering wheel speed signal; 14 - Return fuel line; 15 - System control unit "Airbag" "J234"; 16 - signal "crash" (shock deceleration), via CAN-BUS; 17 - Clamp +30; 18 - Clamp +15; 19 - "Mass" (body); 20 - Power steering pump unit - consists of: a - cover, b - hydraulic fluid receiver, c - pressure limiting valve, d - gear pump, e - electric motor, f - "J500" power steering control unit

The "V119" power steering pump consists of a "d" gear pump and an "e" electric motor. The gear pump is integrated into the power steering pump unit. This gear pump "d" is driven by an electric motor "e", which is also part of the power steering pump unit. Signals for steering wheel rotation speed "13," vehicle speed "10," and engine speed "9" are transmitted to the power steering control unit "f." This power steering control unit regulates the speed of the gear pump's electric motor "e" and, therefore, the volumetric flow of hydraulic fluid.

Restart protection

An integral part of the steering mechanism with electrohydraulic power steering is protection against re-engagement of the power steering drive in the event of a malfunction, after a failure or a traffic accident. After a vehicle accident and after the "crash" signal is displayed on the diagnostic device or on the diagnostic device, it is necessary to deactivate the protection against repeated switching on by resetting the contents of the fault memory. The restart protection can be deactivated by turning off the ignition and starting the engine. If necessary, wait about 15 minutes to allow the power steering pump unit to cool down after overheating. The protection will not be deactivated if there is a fault in the vehicle's electrical system or if the power steering pump unit is damaged. In this case, it is necessary to implement automatic control (self-diagnosis) and, if necessary, replace the pump unit.

TRW Power Steering Assembly Diagram

Important: In the event of a vehicle accident and subsequent damage to the front suspension (chassis), the steering system component must always be replaced. Repair of the power steering gear housing is not provided. In case of complaints, the cause must be identified by means of pressure and tightness testing or by means of automatic control. If the fault is located in the power steering gear housing, excluding the power steering sensor, then the power steering gear housing must be replaced. Self-locking screws and nuts must be replaced. Welding and straightening work is not permitted on steering components. To lubricate the rack, use only steering gear housing grease. Oil type: Hydraulic fluid. The amount of liquid (oil) in the system.

1 - Thread-cutting screw, 6 Nm; 2 - Protective sheet; 3 - Cardan shaft with steering column crosspiece; 4 - Screw, 20 Nm + 90°, replace after each removal; 5 - Seal of the power steering sensor "G250" with a detachable wire - item 6, replace after each removal; 6 - Power steering sensor "G250" with detachable wire - pos. 8; 7 - Screw, 6 Nm, power steering sensor "G250" with detachable wire - pos. 6; 8 - Wire; 9 - Nut, self-locking, 20 Nm + 90°, replace after each removal; 10 - Steering trapezoid pendulum arm (from the wheel hub bearing cap); 11 - Fuel return line, pipe screw M 16 x 1.5, power steering housing - pump unit, tightening torque of the pipe screw on the power steering housing: 30 Nm; 12 - O-ring, replace after each removal; 13 - Hollow screw, 35 Nm, replace after each removal, with check valve, M14 x 1.5; 14 - O-ring, replace after each removal; 15 - Pressure line, power steering gear housing - pump unit, tightening torque of the pipe screw on the power steering gear pump unit: 30 Nm; 16 - Power steering; 17 - Beam for fastening the lift, with a recess (see picture), in the event that the exhaust pipe passes under the suspension mounting beam, without recessing (not shown), in the event that the exhaust pipe passes above the suspension mounting beam; 18 - Screw, 50 Nm + 90°, replace after each removal; 19 - Rocker support, the shape of the rocker support depends on the gearbox

Pressure Line Assembly Diagram - TRW Power Steering Gear

1 - Power steering pump unit; 2 - Return fuel line, when removing it, it cannot be disconnected, the bending radius cannot be less than 100 mm; 3 - Pipeline holder; 4 - Power steering; 5 - Pressure line, when removing it must not be disconnected, the bending radius must not be less than 100 mm; 6 - Strut, secured with a clamp in the body; 7 - Wire from the power steering sensor "G250"

Position for pressure line assembly

Between the pressure line "1" and the suspension mounting beam "2" it is necessary to maintain a distance "A" of approximately 10 mm.

Install a suitable spacer washer between the suspension mount beam and the pressure line.

Important: For TRW power steering housings, a new hollow screw must be used.

Hand tighten the pressure line hollow screw with a new seal on the power steering gear housing. Remove the spacer washer between the axle suspension mount beam and the pressure line. Check the distance between the suspension mounting beam and the pressure line and adjust if necessary. Tighten the hollow screw to the specified torque.