C05D6: Power Steering Control Module Processor Performance

What it means

The power steering control module monitors its processor operation and internal checks. It sets this code when the processor reports a performance fault or fails an internal check.

At a glance

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

How it works

The power steering control module runs internal processor checks while managing steering assist. This code sets when the processor reports a performance problem or fails an internal check, which can reduce or remove steering assistance.

Common causes

Most likely first.

1. Module internal fault
2. Module software outdated, reflash may resolve
3. Supply voltage outside specification

Symptoms

• Power steering warning light on
• Power steering assist may be reduced or unavailable

How to diagnose it

1. Read power-steering-module freeze-frame and live data, and check for companion codes that identify voltage, communication, or internal faults.
2. Check battery condition, charging operation, and the module's power and ground connections against the manufacturer's specification.
3. Inspect the power-steering module connectors and harness for corrosion, loose pins, water intrusion, or damage.
4. Clear the code after recording the data, then check whether it returns during a stationary steering test conducted as the manufacturer specifies.
5. If supply and wiring are sound, check the module software level and internal status using the manufacturer's service information before considering module replacement.

Common fixes

• Repair a poor power or ground connection or damaged module wiring.
• Correct a battery or charging-system fault causing out-of-range module voltage.
• Update or reprogram the steering module if an applicable manufacturer update addresses the fault.
• Replace a module that fails its internal checks after supply, wiring, and software have been verified.

Can I keep driving?

Steering effort may rise suddenly or assist may be lost, especially at low speed. Avoid driving if steering is difficult to control; otherwise proceed cautiously to repair and allow extra effort when manoeuvring.