Lane assist, emergency braking and adaptive cruise control all depend on sensors aimed exactly where the factory put them. Several common repairs move them. Here is when recalibration is needed, and why it is not optional.
What ADAS actually is
Advanced driver assistance systems are the cameras, radar units and ultrasonic sensors that feed features most drivers now take for granted: automatic emergency braking, lane keeping and lane departure warning, adaptive cruise control, blind spot monitoring, traffic sign recognition, parking sensors and cameras.
They share one weakness. Every one of them works out where things are in relation to the car by assuming the sensor is pointing exactly where the manufacturer put it. A forward camera behind the windscreen is making judgements about objects a hundred metres away. Move it by a couple of millimetres, or tilt it by a fraction of a degree, and the error at the far end is measured in lane widths.
The repairs that change sensor aim
Calibration is not a service item that comes round at a mileage. It is triggered by work on the car:
- Windscreen replacement. The forward-facing camera is mounted to the glass or to a bracket on it. A new screen means a new mounting position.
- Wheel alignment or any change to geometry. Several systems are referenced to the car's thrust line — the direction the rear axle actually points. Correct the geometry and you have moved that reference.
- Suspension work, or a change in ride height. New springs, new bushes or a different ride height alter the angle at which cameras and radar look at the road.
- Collision repair. Even a modest knock can move a radar behind a bumper or grille.
- Removing or replacing a sensor, camera, radar, bumper or grille — including when it goes back in what looks like the same place.
What the industry requires
This is not simply a garage preference. Thatcham's Insurance Industry Requirements, published in 2020, state that inspection, realignment and calibration requirements must be considered in every situation where ADAS sensors, parts likely to affect how those sensors work, or vehicle geometry are involved in a repair — windscreen replacement explicitly included.
The ADAS Glazing Code of Practice goes further on glass work: the manufacturer's own recommendations should be followed to reinstate correct operation, and where calibration cannot be carried out at the point of replacement, the customer should be told the status of their systems and what is needed to restore them. If a screen has been replaced and nobody mentioned calibration, that is a fair question to ask.
Static and dynamic calibration
| Type | How it is done | What it needs |
|---|---|---|
| Static | Manufacturer-specified targets are set at measured distances and heights in front of the car, and the system is taught where they are | Level floor, controlled lighting, space around the vehicle, correct tyre pressures and a settled ride height |
| Dynamic | The car is driven on the road at specified speeds while the system calibrates against real lane markings and traffic | Suitable roads, clear markings, adequate weather and light |
Which one applies depends on the make, model and system — and plenty of cars need both, in a set order. This is also why calibration cannot sensibly be done on a kerbside: the static procedure depends on a level surface and measured positions, not on an approximation.
What happens if it is skipped
Sometimes a dashboard message or a disabled function makes it obvious. The more troubling case is the one where nothing looks wrong: the system still switches on, still shows as available, and is quietly working from a false idea of where the road is. A lane assist that nudges towards the wrong line, or an emergency braking system that reacts late to something slightly off its assumed centre, is worse than one you know is off.
Alignment and ADAS belong in the same conversation
Because geometry is a reference for these systems, a four-wheel alignment on an ADAS-equipped car may need recalibration afterwards. It is worth settling that before the work starts rather than after — see four-wheel alignment: the symptoms, the angles and when you need it.
Mitsiland carries out ADAS calibration alongside wheel alignment and tyre work at Tameside Business Park in Denton, Manchester, for Land Rover, Jaguar, Audi, Porsche, Bentley and Mitsubishi. If you have had glass, suspension or collision work done and calibration was never mentioned, call 0161 320 7788.
