On most Audis the auto-brake and collision-warning system is badged Audi pre sense, though plenty of owners still call it Front Assist. 'Not available' means the front radar or camera has stopped reading the road. Common on the A4, Q5 and A3. Here's what triggers it and what the fix costs.
You can drive the car. The system that's offline, Front Assist or Audi pre sense, is the automatic emergency braking. While it's unavailable it won't intervene if traffic stops sharply ahead. Normal brakes, steering and cruise all still work. Leave more following distance and treat the car as if the system isn't there until it's fixed.
On an Audi the radar sits behind the front grille and the camera at the top of the windscreen. Front Assist, or pre sense, depends on both. Most faults trace to something that moved one of them, or a repair that skipped the calibration. Find your case below.
The radar behind the Audi grille is aimed to a tight tolerance. Take the front bumper off for a repair or a respray and it almost never returns to that exact angle. The system can't trust the radar's readings, so it shuts pre sense down.
This is the one Audi owners hit most. An independent Audi specialist or a body shop does the mechanical repair perfectly, but ADAS calibration needs separate, specialised equipment that many good garages simply don't have. The car is fixed, the calibration step is missing, and Front Assist stays unavailable. That last step is what our network does.
Audi owners fit a lot of front-end styling, RS-style grilles especially. The radar transmits through the grille area, so a replacement grille of a different design or thickness can scatter or block the signal. If pre sense dropped out after a styling change, start there.
Pre sense uses a camera at the top of the windscreen alongside the radar. A new windscreen moves that camera, and it has to be recalibrated for the system to work. Windscreen fitters often can't do that step, so pre sense drops out a few miles after the glass job.
If the front radar or a control module was replaced, perhaps after front-end damage, a new unit isn't plug-and-play. It has to be coded to your car and then calibrated. Skip either step and Front Assist won't come back.
Road salt, packed snow or heavy grime over the radar behind the grille badge can be enough on its own. This is the one to rule out yourself: clean the area, restart the car, and check before booking anything.
Two codes come up on Audis with this warning. C110300 means the radar can't complete its calibration. U023500 means the car has lost communication with the front distance sensor, one we see on the Q5 in particular. Both are calibration jobs, not a failed radar.
Worth a quick check first: clear any dirt or ice off the radar behind the front grille badge, wipe the inside of the windscreen by the camera, and restart the car. If 'Front Assist not available' or the pre sense warning is still up, the system needs recalibrating.
The fix is a fixed £349 through our network, with the diagnostic scan and a calibration certificate included. If the scan shows the radar or a module has failed, you'll know the cost before any work starts.
There's no charge for the diagnostic if you decide not to go ahead. See how ADAS calibration works for the full procedure.
Pricing is fixed across our network. Same price wherever you are in the UK. Your tier is set by what work has been done, not by your postcode or your car's make.
All prices include the diagnostic scan, the calibration procedure (static, dynamic, or both as required), a post-calibration check, and a calibration certificate. No charge for diagnostic if you decide not to proceed.
Send your registration and a line on what's happened. We'll come back with the fixed price, the nearest accredited workshop, and the soonest available slot.
That's normal, and it isn't them cutting corners. ADAS calibration needs dedicated target equipment and software that most independent garages don't carry, even excellent Audi specialists. The mechanical repair they did is fine. What's left is the calibration, and that's the single job our network handles. The repair garage does the car, an accredited calibration workshop finishes the ADAS step.
Effectively, yes. Front Assist is the VW Group name for forward collision warning and automatic emergency braking. Audi badges its version Audi pre sense, or pre sense front. Same job, same radar-and-camera hardware, same calibration. Whether your dash shows 'Front Assist' or 'pre sense', the fault and the fix are identical.
Radar calibration is a fixed £349 across our network, the same price wherever you are in the UK. That covers the diagnostic scan, the calibration, and a calibration certificate. If the scan shows the radar or a module has failed and needs replacing, you'll know the cost before any work goes ahead. No charge for the diagnostic if you decide not to proceed.
On the A4 and Q5, front-end work is the trigger we see most. A bumper repair, a refitted or restyled grille, or a collision repair all shift the radar's aim. A windscreen replacement does it through the camera. A common thread on Audis is a repair completed without the calibration step, which leaves the warning on even though the car looks sorted.
Pre sense, adaptive cruise and lane assist share the same front radar and camera. If your Audi is flagging more than one, a single calibration visit usually clears them together.
The same system under its Audi name. Start here if your dash says pre sense.
Bumper work is the top trigger. The dedicated guide if that's your case.