Audi A4 B9 / B9.5 — Lane Assist (Active Lane Keeping) Activation

Your A4's front camera already sees the lane lines — this activation turns them into steering corrections. QK1 camera required. Includes app ON/OFF toggle if you don't retrofit the OEM button.

€50

One-time · Permanent VIN-verified Same-day confirmation

What You Get

Enables factory Lane Assist (Active Lane Keeping) on any Audi A4 B9 / B9.5 fitted with the PR-QK1 front camera. Lane Assist reads the road markings ahead of you and applies gentle steering corrections when the car starts drifting out of its lane without a turn signal — plus an audible / visual warning if you keep drifting. From factory Audi provides a dedicated button on the indicator / wiper stalk to turn Lane Assist on and off. If you retrofit that OEM button we code it in for you. If you don't retrofit the button, the RetroLab Pro app gives you a 1-click Lane Assist ON/OFF toggle at zero extra cost — included in the €50 activation. Performed through a guided, VIN-specific OEM workflow — no dealer, no remote session, no manual scripts.

How It Changes Behavior

From factorythe A4's PR-QK1 front camera is already tracking lane markings on every drive, but the steering column does not react to the data — the car lets you drift out of the lane with no corrective steering, no warning, no visual cue in the cluster.

After activationLane Assist reads the road markings live: the car applies gentle corrective steering to keep you in your lane, warns you visually in the cluster / Virtual Cockpit if you cross a line without indicating, and can be enabled or disabled with a single click — either from the OEM stalk button if fitted, or from the RetroLab Pro app if not.