Audi SQ5 (2011 – 2018) Electric Power Steering Rack

The Audi SQ5 (2011–2018) is the heaviest car in this range — a tall, performance-oriented SUV — and that matters when its power steering fails. The SQ5’s rack is electromechanical, with the assist motor and control module integrated into the rack rather than driven by a hydraulic pump. On a vehicle this heavy the motor is doing the most work of any model here, so when the internal electronics fail the loss of assistance is the most dramatic of the lot: the wheel becomes genuinely hard to turn at parking speed. We repair the SQ5’s original rack and steering ECU at component level and return the same unit.

Why the loss of assistance is so pronounced

The failure announces itself with the red “Steering defective! Do not drive vehicle!” message on the cluster. Treat it exactly as written — do not continue driving the SQ5 once it appears.

• Red “Steering defective! Do not drive vehicle!” warning on the cluster
• Very heavy, unassisted steering — the SQ5’s kerb weight makes the effort far more obvious than on a saloon
• Sudden loss of assistance, in some cases reported at higher road speeds
• Steering that no longer self-centres after a turn
• The warning starting intermittently before it settles on permanently

The fault codes behind it

Scanned, the SQ5 rack typically returns two codes:

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

Both are internal to the rack’s own electronics rather than to the tie rods, column or loom — which is why a dealer scan tends to end with a complete rack replacement quote.

What fails inside the rack

The weak points are inside the rack’s integrated steering ECU. The motor position sensor (C10AD29) stops reporting the assist motor’s position reliably, so the module shuts assistance down rather than trust unreliable feedback. The control module’s own circuitry can also fail internally (B200049). The mechanical rack and pinion are almost always sound — on a heavy SUV that works its steering hard, it is the sensor and control board that fatigue first.

Repairing the SQ5 rack instead of replacing it

Because the fault is in the internal electronics, your SQ5’s original rack can be repaired at component level rather than replaced with a complete new assembly. Ours is a mail-in repair-and-return service: send us the failing rack and steering ECU, and our engineers carry out circuit-level board repair on the sensor and control module before returning your own unit, repaired to meet or exceed OE specification with the weak points reinforced. Given how hard the assist motor works on a vehicle this heavy, every unit is proven on our in-house Hardware-in-the-Loop rigs — which simulate real load, heat and vibration — before it leaves us, and most remanufactured parts carry a lifetime, unlimited-mileage warranty.

When your order is complete, print the repair form, jot down the warning and symptoms your SQ5 has shown, and drop it in the box with the rack — or forward it to us beforehand. It keeps your unit matched to your details from the moment it lands with our team. Not certain the rack is the failed component? Our broader electric power steering repair service covers the related steering electronics too.