- Advanced tech makes windshield replacement expensive
- What was routine repair can cost thousands
- Some repairs exceed $1,500
- Aligning cameras and sensors add to cost
A rock cracks the windshield, what do you do? If you think a replacement windshield can be installed while the car is sitting on your driveway for $200 or $300, think again.
If your vehicle is equipped with rain sensing wipers and such advanced driver-assistance systems as automatic braking and adaptive cruise control be prepared to spend $2,000 maybe more for a replacement windshield, recalibrating safety features and performing a mandatory thrust wheel alignment (which ensures the driving wheels are in proper alignment with the non-driving wheels). Even a replacement windshield for a vehicle with head up display that does not have driver-assistance systems and rain sensing wipers can easily cost over $1,500.
Driver assists, head-up displays to blame
Head-up displays, HUD for short, and advanced driver-assistance systems, commonly known as ADAS, are now offered in a wide variety of vehicles. Once reserved for luxury cars, HUD, ADAS and rain sensing wipers are available on Chevrolet, Ford, Hyundai, Kia and other mainstream vehicles.
Among the other ADAS safety features commonly seen today are adaptive headlights, forward collision warning and lane keep assist. Some of these safety features are standard, some are available in option packages. Radar positioned on the front of the car detects an object and a camera located in the grille or behind the windshield identifies the object as a car or pedestrian, for example.
For HUD, ADAS and rain sensing wipers to work properly a special replacement windshield must be installed.
Original-equipment glass recommended
“It is really critical for cars that have ADAS and head up display that you have a windshield that is either an OEM, original equipment part, or one that meets the very strict standards for optical clarity and lack of distortion set by GM, Mercedes or whoever it happens to be” for that vehicle,” said Michael Calkins, manager of technical services in AAA’s engineering and repair department.
“If those standards are not met, the sensors are not going to function properly and your lane keeping, automatic emergency braking, whatever it happens to be that those cameras support, are not going to be 100 percent efficient and effective,” Calkins said. The rain sensor also may not activate if it cannot determine the amount of water that is on the windshield. Simply, the end result could be an accident because the systems did not work as engineered.
Distortion is another issue. It is important that the body shop or glass company know the vehicle’s year, brand, model and vehicle identification number so the correct replacement windshield is installed. For example, there are 11 replacement windshields for a 2017 Hyundai Santa Fe, according to Safelite AutoGlass.
Wrong windshield spells trouble
If the wrong replacement windshield is installed in a vehicle that has head up display, “you would get a ghosted or double image. You will see actual separation. Let’s say the speed of the vehicle is 60 mph. You will see two 6s, you will see a secondary 6 floating above the primary 6,” said Mike Richardson, General Motors’ technical expert for fixed glass and glazing.
HUD uses a projector positioned in the instrument panel to project a digital transparent image on the vehicle’s windshield in front of the driver. The data is the same information located in the instrument panel. The purpose of HUD is to keep important data clustered together on the windshield in front of the driver’s eyes in order to reduce the amount of time the driver’s eyes are not on the road. The end result is expected to be fewer accidents. But if the data is difficult to read, blurry, it could cause an accident.
Other information projected on the windshield can be turn-by-turn navigation information, speed limit signs, speedometer, cruise setting speed, warning lights such as low fuel, lane keeping assist information, blind-spot collision warning, and audio information.
HUDs a small, but growing concern
Although General Motors introduced the first production car with head up display in 1988 consumers have not seen a great need for this option. Ed Sprigler, vice president of strategic initiatives, Safelite AutoGlass, said only 1.39 percent of that company’s replacement windshields installed last year had HUD, up from 0.37 percent five years earlier. “We expect the pace to increase,” Sprigler said.
To prevent the digital image from ghosting or creating a double image on the windshield, a sheet of polyvinyl butyral, a resin, is inserted between the two windshield layers in the rectangular area where the digital information is projected. The transparent vinyl has a wedge pattern that prevents the images reflected on the windshield from ghosting.
However, not every brand requires a special windshield for head up display. Among the exceptions are the 2019 Mazda6 and Mini models as well as the 2020 Ford Escape which use a small plastic lens located on top of the instrument panel that folds down when not in use. The information is reflected off the lens not on the windshield.
Rain-sensing wipers, driver assists require special treatment
Rain sensing wipers and ADAS are becoming more common. Approximately 12 percent of the 4.9 million replacement windshields Safelite AutoGlass installed in 2018 had a rain sensor application to automatically turn on the wipers, compared with 7.4 percent in 2014. Last year 7.1 percent of Safelite’s replacement windshields had a front camera located behind the windshield that operated ADAS, up from 0.75 percent in 2014.
Vehicles equipped with ADAS and rain sensing wipers require more work than popping out the broken windshield and installing a replacement. The next step is a thrust wheel alignment to make sure the rear wheels are lined up directly behind the front wheels and not 1, 2 or more degrees off. If misaligned, the driver assists may not activate when needed.
Recalibration is the key
Finally, ADAS needs to be recalibrated. There are two types of ADAS: Most German and Asian brands use a static target system and domestic brands generally use a dynamic system. There also are a few brands that use both.
Vehicles with a static system are complicated to recalibrate and require a building with a large amount of level, unobstructed space where targets can be positioned.
“Let’s say you want to recalibrate the front radar sensors and front camera on a Honda Odyssey. You need 57 feet of unobstructed space, no metal objects, that’s fore and aft. Then you need 16 feet either side of the vehicle, unobstructed with no metal objects,” said Jim Moritz, global technical trainer for an international automotive tool and equipment manufacturing company.
“Who the heck has that kind of space to do this? They are subcontracting it to shops that have converted warehouses where they know they have perfectly level floors, have unobstructed space to do these calibrations,” Moritz said. Recalibrating the system to recognize targets can take 3 hours.
Dynamic ADAS is less complicated. A special tool is connected to the vehicle’s OBD2 port under the instrument panel to start the recalibration process, then the vehicle is taken on the road and driven at specific speeds in order to relearn such things as road markings and obstacles. The process can take 30 minutes to one hour.
Making the right choice
Selecting a replacement windshield is complicated. Check with the dealer and aftermarket auto glass companies to determine which replacement windshield is required, whether it needs to be engineered for HUD, ADAS and rain sensing wipers or if a bare-bones windshield is sufficient.
“Most people have no idea what is on their car,” Sprigler said. “When they take delivery of a new car they are probably spending more time with the sales professional on the infotainment system and not on the vehicle’s safety attributes. Think about how long it took people to understand how to use anti-lock brakes.”