Warning for people replacing their car’s windscreen

South Africans with cars equipped with Advanced Driver Assistance Systems (ADAS) have been warned to be careful when replacing damaged windscreens, as they may contain critical system components.

This is according to the Automobile Association of South Africa (AA), which noted that one in five cars produced globally today features ADAS, including automatic braking, lane keeping, and even reads and displays traffic signs.

Additionally, these cars can maintain following distances, adjust headlight brightness in oncoming traffic, assist with parking, or even create augmented reality heads-up displays.

“But here’s what most owners don’t realise: replace a windscreen and your ADAS camera needs to be recalibrated to function effectively,” warned the AA.

“Think of it as dropping your favourite set of bifocals and a lens shifting due to the impact; it alters what and how you see. ADAS is no different.”

ADAS features use groups of sensors to detect and analyse a vehicle’s driving environment, including ultrasonic, LiDAR (light detection and ranging), radar and mono, stereo, and trifocal cameras.

Unfortunately, when it comes to replacing broken, cracked, or damaged car windscreens, many of these are located on the upper, inner surface of the windscreen.

Manufacturing guidelines for ADAS-equipped vehicles include recalibration after any glass replacement or camera removal, so the safety system software learns the new camera position.

“Due to normal manufacturing tolerances of the windscreen and the camera bracket, the camera will be pointing in a different direction following the installation of a new windscreen,” the AA explained.

If an ADAS-fitted windscreen has been replaced but not calibrated, the following may occur:

• Incorrect functionality, loss, or reduced accuracy of ADAS functions
• False alarms or no alerts at all, creating unpredictable ADAS behaviour
• Increased accident risk because systems may fail to engage or activate incorrectly
• Legal and insurance implications, as many insurers require proof of recalibration after windshield replacement

“A one-degree misalignment can cause an error of approximately 2.4 metres over a distance of 30 metres, which is critical at highway speeds,” it added.

Workshop diagnostic scans

Major local windscreen repairer PG Glass said that it is concerning that manufacturer workshop diagnostic scans do not show a fault code for a missing or inaccurate recalibration.

A diagnostic scan may highlight existing vehicle diagnostic codes, but won’t indicate whether recalibration is required, creating confusion because the car may appear “fault-free” even though ADAS is compromised.

According to PG Glass, only recalibration ensures correct camera functionality for ADAS features, making it a safety-critical blind spot for local modern-car owners. 

If it is not done after a windscreen replacement, the ADAS may use its original reference point, which is incorrect if the camera position or orientation has changed.

This could lead to critical safety-feature malfunctions, since tests show that miscalibrated cameras cause the automatic braking to fail, resulting in collisions, or vehicles deviating from their lanes due to failed lane-keeping assistance.

“The very first ADAS recalibration took place globally in 2014. Over five million vehicles were recalibrated globally, post a windscreen replacement, in 2025 alone,” explained Eddie Irving, Head of New Markets at PG Glass parent company Belron.

“ADAS systems in cars in South Africa are growing significantly, with forward-facing cameras in the local car parc growing from around 2% in 2020 to 17% at the end of 2024. We need local motorists to understand the safety and importance of ADAS recalibration.”

AA CEO Bobby Ramagwede added that the organisation sees recalibration as equivalent to a vehicle recall, as it is critical for effective modern vehicle safety parameters.

“Ensuring your ADAS system is working at peak performance is a no-brainer, especially when you factor in that a Dutch insurance body study involving one million cars between 2019 and 2021 showed up to 50% fewer accidents in vehicles with functional Front Collision Warning systems,” he said.

“Functioning ADAS means protected driver, protected passengers and protected road users, including cyclists and pedestrians.”