Why ADAS belongs on the used-car checklist
A modern pre-purchase inspection should consider more than the engine, transmission, tyres and body. Cameras, radar and other sensors may support automatic emergency braking, adaptive cruise control, lane assistance, blind-spot monitoring and parking functions.
Damage, incorrect parts or incomplete repairs can leave these systems unavailable or operating outside their intended conditions. Some problems are obvious; others need diagnostic equipment and service information.
Confirm what the vehicle actually has
Features vary by model year, variant and option pack. Do not rely only on an advertisement or a row of buttons.
Use the owner’s manual, build information or a dealer-equipped vehicle lookup to identify the fitted systems. Ask the seller to demonstrate the settings and explain any feature they say is present.
Inspect the windscreen and camera area
Look through and around the area near the interior mirror where a forward-facing camera is commonly mounted.
Check for:
- cracks, chips, scratches or contamination in the viewing area
- a camera cover or bracket that appears loose or disturbed
- stickers, accessories or tint intruding into the camera’s view
- evidence that the windscreen has been replaced
- invoices showing the correct glass and any required calibration or verification
A replacement windscreen is not automatically a problem. Missing records, unsuitable glass or an incomplete camera procedure are the concerns.
Inspect bumpers, grilles and sensor zones
Radar and ultrasonic sensors may sit behind emblems, grilles or painted bumper surfaces. Look for uneven panel gaps, impact marks, cracked brackets, heavy filler, poor refinishing or non-standard accessories.
Bull bars, number-plate mounts, driving lights, wraps and replacement grilles can affect a sensor if they obstruct its field of view or change the specified material in front of it. Their presence does not prove a fault, but it should prompt a check against manufacturer and accessory-fitment information.
Watch the instrument check
Before starting the engine, observe the normal warning-lamp check described in the owner’s manual. After startup, note any ADAS warning, “system unavailable” message or feature that cannot be selected.
Do not assume a clear dashboard proves the systems are correctly calibrated. Some alignment problems may not produce a persistent warning.
Review the repair history
Ask specifically about:
- windscreen replacement
- front or rear bumper repairs
- collision and structural repairs
- camera, radar or control-module replacement
- wheel alignment, steering or suspension work
- software updates or recalls
Where the vehicle manufacturer required calibration, look for a report that identifies the vehicle, procedure, result and date. A line saying “codes cleared” is not equivalent to calibration evidence.
Use a sensible test drive
Familiarise yourself with the controls before moving. On a suitable road and within all road rules, observe whether available convenience functions recognise their operating conditions and whether any warnings appear.
Do not stage a collision, drive toward an object or deliberately depart a lane to test a safety intervention. A normal road test cannot prove the complete performance of AEB or other emergency functions.
Get an ADAS-aware pre-purchase inspection
For a vehicle with significant repair history—or whenever the visual checks raise doubts—use a technician who can identify the fitted systems and access appropriate diagnostic and repair information.
The inspection may need a full-vehicle scan, physical sensor and mounting checks, tyre and alignment checks, software or campaign checks, and confirmation of calibration requirements. Not every pre-purchase inspection includes these tasks, so agree on the scope first.
Questions to ask before paying
- Which ADAS functions are fitted to this exact vehicle?
- Has the windscreen, bumper, suspension or any sensor been replaced or repaired?
- Are calibration and diagnostic reports available?
- Are there unresolved warning messages, recalls or software campaigns?
- Does the inspection specifically cover ADAS equipment?
- If further work is required, who has quoted it and what assumptions are in that quote?
Key point
An ADAS concern does not automatically make a vehicle a bad purchase. It does change the information you need. Identify the systems, inspect their physical surroundings, verify the repair history and price any unresolved work before committing.