C0559: Power Steering Control Module Range/Performance – Rear

What it means

Rear power steering control module reading implausible (rear-wheel-steering or rear-axle steering systems).

At a glance

• Usually lights the ABS or stability-control warning light
• The engine or gearbox may go into limp mode

How it works

In vehicles equipped with rear-wheel steering, the rear power steering control module monitors feedback about the rear steering system’s position or operation. This code sets when the rear module’s reading is outside the plausible operating range or does not perform as expected.

Common causes

Most likely first.

1. Module reading drifted
2. Sensor element aged beyond calibration window
3. Sensor mounting loose - signal damping

Symptoms

• Power-steering or chassis warning light
• Rear-wheel-steering function may be limited, if equipped

How to diagnose it

1. Scan the rear steering module for related codes and freeze-frame data to identify when its reading became implausible.
2. Check live rear steering sensor or position data for drift, jumps, or values that disagree with other available steering data.
3. Inspect the rear module’s sensor and mounting for looseness or movement that could damp or distort its reading.
4. Check the rear steering module’s connectors and wiring for corrosion, damage, poor seating, or supply and ground problems.
5. If mounting and wiring are sound, test the sensor and module according to the manufacturer’s diagnostic procedure.

Common fixes

• Secure a loose rear steering sensor or its mounting.
• Repair damaged or poorly connected wiring at the rear steering module.
• Replace a sensor that has drifted beyond its calibration range, if separately serviceable.
• Complete the manufacturer-specified calibration or setup after repair.

Can I keep driving?

If rear-wheel steering is limited, handling at low or higher speeds may differ from normal. Drive cautiously and avoid abrupt manoeuvres; stop if steering behaviour becomes unpredictable.