Audi RS5 (2011 – 2018) Electric Power Steering Rack

The Audi RS5 (B8, 2011–2018) is a high-performance V8 coupe that spends its life being driven hard — and the heat and vibration that come with that are exactly what wears out the electronics inside its power steering rack. The RS5 uses an electromechanical EPS rack: the assist motor and control module are built into the rack, with no hydraulic pump. When those internal electronics fail, the assistance drops out without warning. We repair the RS5’s original rack and steering ECU at component level, reinforcing the known weak points, and return your own unit rather than a replacement carrying the same flaw.

What fails, and why

The failure is electronic, and it sits inside the rack’s integrated steering ECU. The motor position sensor stops reporting the assist motor’s position reliably, so the control module shuts assistance down rather than act on feedback it cannot trust. The control board’s own circuitry can also fail internally. On a car driven as hard as the RS5, it is the repeated thermal cycling and vibration that fatigue the sensor and control electronics — the mechanical rack and pinion are almost always fine.

The warning and symptoms

The tell-tale is the red “Steering defective! Do not drive vehicle!” message. It should be read literally — stop driving the RS5 once it shows.

• Red “Steering defective! Do not drive vehicle!” cluster warning
• Steering turning heavy and unassisted, most obvious at low speed
• Loss of self-centre as the wheel unwinds out of a corner
• Assistance cutting out suddenly, sometimes at speed

The fault codes

• C10AD29 — Motor Position Sensor
• B200049 — Internal Control Module Error

Both are internal to the rack’s electronics, not the suspension or loom, which is why a dealer’s only offer is usually a complete new rack.

Component-level repair of your RS5 rack

Because the fault sits in the sensor and control electronics, your RS5’s original rack can be repaired at component level rather than scrapped for a new assembly. This is a mail-in repair-and-return service: our engineers carry out circuit-level board repair on the sensor and control module, then program and calibrate the unit with dealer-level diagnostic tools before returning your own rack — repaired to meet or exceed OE specification with the weak points reinforced. A complete replacement rack for a low-volume performance coupé like the RS5 is expensive and can be slow to source, and a used unit only carries the same ageing electronics — repairing your own sidesteps both the wait and the risk of inheriting another car’s impending failure. Most remanufactured parts carry a lifetime, unlimited-mileage warranty, and keeping the original rack means the RS5’s coding stays intact.

After payment, print the repair form, add the fault codes and symptoms, and include it in the box with your RS5 rack — you’re welcome to send it ahead of the unit as well. It ensures the repair begins without delay once your rack is with us. If you’re unsure whether the rack rather than another part has failed, our wider electric power steering repair service sets out what else we rebuild.