Symptoms and diagnostic methods for sensor, wiring and software faults in EPS systems – and the role of the MS561 tester, explained by MSG Equipment.
Electric power steering (EPS) is now standard on passenger cars, underpinning fuel savings, safety features, automatic parking and driver assistance. MSG Equipment notes that EPS faults can make a car dangerous, yet experienced technicians can often repair them without replacing the rack.
The article summarises common faults:
- Sensor malfunction – uneven response or loss of assistance in one direction; read fault codes and check the torque sensor on a removed rack activated by the MS561, using an oscilloscope.
- Wiring issues – intermittent disconnections; inspect connections with a multimeter and wiring tester.
- Software problems – sudden unexplained loss of assistance; examine the control unit.