EHPS pump faults may come from the motor, control unit, hydraulic section or wiring. MSG Equipment explains a comprehensive diagnostic approach.
The electrohydraulic power steering (EHPS) pump is a complex unit that directly affects comfort and safety. MSG Equipment notes that symptoms such as heavy steering, pump noise or fault codes look alike across many faults, so only professional diagnostics reveals the real cause.
The article groups typical faults into four areas:
- electric motor – worn brushes and bearings, overheated or shorted windings,
- control unit – failed power transistors, damaged chips or software errors,
- hydraulic section – pressure loss from worn vanes and housing, seal leaks,
- wiring – broken wires or oxidised connectors that cut CAN, FlexRay or PWM communication.
For full diagnostics, it recommends testing both the electrical and hydraulic sides together using the MS561 PRO and MS511 testers.