Let’s Talk about OEM Glass and Calibration

Since the introduction of Advanced Driver Assist Systems (ADAS), the need for aftermarket glass replacement companies to use OEM glass has increased substantially. Of course, auto dealers have claimed for years that OEM glass was necessary for the proper operation of the many electronic systems that utilize the glass for mounting or delivery. Is this true?

I got an email recently from a glass shop that installed a top quality windshield in a Cadillac Escalade with the Cadillac Intelligent Collision Avoidance System. It was installed more than six months ago with absolutely no problems with any of the ADAS system components. As a matter of fact, the customer used all of the system components during several road trips. However, recently the cruise control stopped working. None of the other systems malfunctioned but the cruise control didn’t work at all. The customer took the vehicle to the dealer, where another glass company came in and claimed that the malfunction was caused because the original aftermarket replacement shop didn’t use an OEM windshield.

This troubled me. In my experience, the cruise control malfunction could not possibly be caused by the glass if everything worked for six months prior. The features on the Cadillac glass are interconnected to the other components of the system and if one does not work, the others will not work either. Most concerning is that the statement, “the glass wasn’t OEM glass.” It came from another glass company and not from the dealer who may have had an incentive to sell his own glass.

So, what are we to believe?

I hope our readers can help me find out. I have had reports of ADAS that could not be calibrated unless an OEM glass was used. I have heard that aftermarket Chinese parts worked well with some systems and not others. I have heard that curvature, color intensity and thickness all play a part in proper operation. I have always depended on information I glean from my friends in the glass manufacturing industry, coupled with reports I get from trusted technicians and colleagues from the field. I then test things out with personal experience. However, the questions of ADAS and aftermarket glass replacement are too numerous (and growing) for this method of research.

There are many different ADAS systems out there and all are systems that work well. However, some are more sophisticated than others and some require more exact specifications from other supporting equipment. If you have read my past postings then you know that there has been a wide range of reports and facts. Honda requires OEM glass for proper ADAS operation. All ADAS equipped vehicles require re-calibration. And ADAS in Cadillacs and other GM vehicles require no re-calibration. All these past postings are correct in their content but none of them have given us a definitive answer to all our questions.

So, I am sending out a request to technicians, manufacturers of glass and vehicles, technology gurus of all types to give us answers. I don’t want to hear the politically correct response. I want to hear the truth. Does the glass make a difference in how the ADAS systems work? If so, how? If a system is so delicate and precise that a slight difference in the glass would cause it to malfunction, what about rain, snow, ice, fog, condensation, bug guts, sand pits, rock chips or anything else that affects driver vision? Do these factors affect operation as well? I will be updating you in future blogs with the information I discover.