ADAS Recalibration After Windscreen Replacement

 

 

 

Have you had your windscreen replaced recently? Is your car equipped with an Advanced Driver-Assistance System? Were you advised (or even warned) about the need to recalibrate that device? Whether your ‘smart’ windscreen has been replaced or not, there is a realistic chance that it might need to be in the future, and this is where you could be faced with more questions… or perhaps not. The subject of recalibrating ADAS devices is a Pandora’s Box full of unsubstantiated claims.

For those new to the technology, some background: ADAS systems are designed and developed to automate and enhance vehicle systems for safer and better driving. These features are designed to help with monitoring, warning, braking, and steering tasks. ADAS relies on inputs from multiple data sources, including automotive imaging, LiDAR, RADAR, image processing and computer vision. These devices are mounted in various places in and around the vehicle; some are mounted behind the windscreen.

ADAS

Advanced Driver-Assistance Systems

Advanced driver-assistance systems are one of the fastest-growing segments in automotive electronics. In terms of car design and evolution, motorists are in safe hands. Ultimately, and until we have autonomous vehicles, the motorist’s hands should however still be on the steering wheel.

Does your camera (or device) need recalibrating after the windscreen has been replaced?

There are a variety of factors to consider, but to cover all bases the blanket response would be to say yes it does. However, before the recalibration apparatus was made available to repair shops, windscreens on cars with ADAS were still being replaced. If the answer is to be yes, why haven’t those vehicles been recalled? The counter argument to that could also be that none of those vehicles needed adjustment, or even, none of them went into default mode after having the windscreen replaced and, worse still, crashed as a result of a misaligned device. There are no reported cases of crashes, injuries or fatalities which were attributed to an uncalibrated camera. Meanwhile, the same cameras are still being recalibrated today.

A motorist emailed me to ask if his device needed calibrating post windscreen replacement. His vehicle featured ‘road sign assist’ which he said he didn’t use anyway. The company who were replacing his windscreen stated that he must drive the car to another one of their sites (30 miles away) to have the camera recalibrated. There was an additional cost implication to this procedure (over £150) as well as his time and fuel to get him there and back. If it was – according the repairer – paramount for his safety why were they sending him on his way, in the compromised car, to another destination 30 miles away? He went ahead and had his windscreen replaced but decided against the recalibration procedure on the basis that he didn’t agree with paying what they were asking for, and then having to embark on a 60-mile round trip in order to get it. Interestingly, he later had his vehicle checked by a manufacturer main agent and there were no flags or faults in the vehicles computer system. Everything worked as it should. The Road Sign Assist device checked out okay.

Traffic Sign Assist

When replacing the windscreen on a vehicle, if the windscreen is a genuine OE product and you are fitting it using the correct bump-stops/trims/damming/mounting components, and within OEM tolerances, as long as you do not disconnect the ADAS device and put the vehicle through an ignition cycle, there is nothing to detect the new part.

Put simply, if you are using manufacturer branded products, fitting them to millimeter precision, and do not put the vehicle through an ignition cycle [with a device disconnected] the car will not know the windscreen has been replaced. It is therefore unlikely that you will encounter any issues. Furthermore, many (if not most) devices are auto-calibrating. They have to be, to allow for constant variables during use. The issues occur mostly (in terms of windscreen replacement) when non-genuine parts are used (referred to as aftermarket parts). Comparing an OE windscreen to an aftermarket copy of it, the differences often become immediately apparent such as misaligned brackets (to which the ADAS device is mounted) or that the material used is inferior. When you mount a camera to its bracket or plate which itself is not positioned correctly, the accuracy of that device is immediately compromised. This therefore, is a scenario where recalibration would be needed. Original parts do not offer any such issues.

The (American-based) Insurance Institute for Highway Safety conducted testing of windscreen-mounted advanced driver assistance systems in 2017 and found that a misaligned camera [on a test vehicle] led to issues with the vehicle’s autobraking and lane-departure warning functions. Honda Collision Marketing Assistant Manager Scott Kaboos summarised after the research that Honda required OEM windscreens be used and that they had seen “many issues” where aftermarket glass led to a situation where the calibration would not “take properly.” After the [repair] shop replaced the windscreen with an OEM edition, “everything worked fine again.” Kaboos stated.

IIHS senior test coordinator Sean O’Malley stated that this demonstrated the need for calibration rather than a ban on aftermarket parts concluding that, “The bottom line is that it could still be calibrated to work as intended.” While a factory-misaligned bracket was found on an aftermarket windscreen, the IIHS found no real issues with aftermarket glass itself, according to O’Malley. Chemical composition, laser refraction and refractive index testing found largely that ‘glass is glass’.

In the UK there have been no reports or stories in the press about firms – nor individuals – being taken to task over negligence. Why? Is it because there have yet not (and thankfully)  been any incidents? Could it also be that there actually isn’t any requirement for an installer to carry out a recalibration? In the same way that any Fred-in-a-shed-with-a-bag-of-tools can replace a windscreen among all the cries of how important structural rigidity is, and how airbags rely on the windscreen to be adequately bonded in order to be effective (provided the occupants are wearing seatbelts in the first instance) anyone can also replace the windscreen on a car equipped with ADAS technology. Is it compulsory to recalibrate those devices? No. Is it necessary to recalibrate them? Maybe.

Whether recalibration is compulsory (after windscreen replacement) or not, are they being checked correctly? Where are the before and after test results? Who is regulating that part of the industry? Who is policing it? How do we know that the procedure was actually carried out? Where is the second printout showing how much adjustment is or was needed? Proof? Is it merely a box-ticking exercise to distance from blame, or something to staple to the invoice to validate the extra charge?

This is a subject that will run for a while, and during that time the ones making the loudest claims in favour of recalibration are also looking for a return on their investment into what is being sold throughout the motor industry as a revenue stream.

Have you had an experience to do with ADAS and windscreen replacement, good, bad or indifferent? Please get in touch.

 

 

Tailgate Glass Transplant

 

 

 

Some of the unsung work we, as windscreen fitters do, is in bodyshops (or accident repair centres). Working as the subcontractor for a crash repair garage can be bread and butter for some firms or the staple income for a lot of windscreen companies. Here is an example of a quick turnaround job: the tailgate transplant.

The new tailgate is painted as the old, crashed one is removed from the car and stored. On the day of the swap, the new painted tailgate will be hung on the car, and work to transfer all the parts begins. The bodyshop fitter will remove all the parts leaving the glass to the specialist:

Tailgate Transplant

The donor tailgate

There are various ways to remove the glass, some methods are better than others. This glass was removed with a square-profiled wire.

Heated rear windscreen removed

Work then begins or preparing the newly painted tailgate. A minimum period of 24 hours must pass after bake before a bonded application can be introduced to fresh paint. With this in mind, a few checks are still necessary to satisfy the installer that the substrate is suitable for bonding to. The new tailgate preparation begins:

New tailgate

There are many polyurethane adhesives on the market. For this job, Sika’s Sikatack Drive was used. Despite its excellent primer-less application, the manufacturer recommends use of a primer – or adhesion promoter – on freshly painted surfaces. But before that, the surface is ‘scratched’ over the bond line to provide a ‘key’ for the primer to adhere to:

Surface preparation: key

Following Sika’s guidelines, the surface is ‘activated’ as preparation for the primer, but also to remove any particles of dust or contaminants. After observing the requisite flash off time, the (black) primer can now be applied:

Adhesion promoter by Sika.

Whilst the primer dries, the glass can be prepared. This is a delicate process of cutting back the old cured adhesive and cleaning the surface. Care is taken not to catch or damage ant hardware on the glass, especially the heater elements. Again, following manufacturer instructions, the  glass  is  prepared  before  fresh  (polyurethane)  adhesive ( “PUR” )is applied. The glass is marked indicating the date, the installer’s identification as well as the corresponding batch numbers for the PUR for traceability.

Heated rear windscreen

Finally, the ‘transplanted’ heated rear windscreen:

Peugeot 3008 glass transplant

Comments and questions welcome.

Manufacturer Warranty: Windscreens

 

 

I replaced a windscreen for an Audi dealer, however, there was nothing wrong with the glass. I asked what the change was for, and it was pointed out that there was an issue with the automatic rain and light sensor. So why was the windscreen cited as the issue?

In his report, the investigating Audi technician concluded that the sensor was not functioning due to the car having a non-genuine windscreen replacement; the (aftermarket screen in it was made by AGC Automotive). As the car was to be sold whilst still under manufacturer warranty the investigation ended there, and could not be resumed until a genuine, Audi branded glass was in place. I duly obliged. However, shortly into the strip-down I discovered what the cause of the issue really was: a damaged rain sensor. The previous installer had damaged the circuit board inside (there were screwdriver marks in the casing).

The car in question was registered in 2016, so much of its warranty would have still been in place; just as long as any parts replaced were authentic, Audi branded.

Rain Sensor 2

Windscreen Rain Sensor

 

Another similar situation unfolded when a Volkswagen main agent was investigating a sensitivity issue on a rain sensor on a fairly new Golf; the owner said the automatic wipers didn’t seem to react as well as he though they should. The VW technician noted the windscreen, an aftermarket version by Saint Gobain (Sekurit) and quickly surmised that it was the cause of the problem. I went along to give a second opinion.

The first place to look for obvious things that could be wrong with a poorly functioning rain sensor is the rain sensor module. I removed the rear view mirror assembly and immediately saw that the rain sensor was not seated properly in the mounting bracket. A push and a click later, the wiper sensitivity was restored to optimum level. However, VW did tell the Golf owner that if there was an issue with the rain sensor (or windscreen) whilst the car was under manufacturer warranty, it would not be covered owing to the non-genuine windscreen in the car.

Whilst these examples may seem excessive, windscreens can be much more complex than the two highlighted here. With radio antennae; heater elements; GPS hardware; Lane Departure Warning sensors; Autonomous Braking hardware; Head Up Display and more, the windscreen is no longer just a piece of glass shielding the car’s occupants from wind and flies. The best available parts, especially if the car is still under warranty (or the more technology connected to the glass) will always be what the vehicle manufacturer endorses.

 

To See, or Not to See

 

 

Now You See It…

An illustration of Before and After stages of a typical windscreen repair. 

Have you recently had your windscreen repaired? Were you pleased with the results? Was there a discernible between the before and after appearances of the damage? Would you know a good repair if you saw one? A lot of repairers don’t, never mind how to achieve one.

Windscreen Repair c

Windscreen Repair

A recent thread on Pistonheads  highlighted a common, and proliferating issue in windscreen stonechip repair. There appears to be a perceived acceptance in what a repaired chip looks like, and judging by a lot of evidence, not many people actually know what an aesthetically, structurally and technically sound repair should look like.

Generally speaking, if there is no difference between the ‘before’ and ‘after’ states, it’s not a good repair. In fact, it is likely that the damage – technically speaking – has not been repaired. “It’s been sealed” was the closing line the TVR Wedge owner got on the Pistonheads thread after he questioned the repairer when he claimed to have finished the job. Looking at the end product of the attempted repair, it could be argued that the repairer had little or no grasp of what he (or she) was doing. Irrespective of what the repairer’s assessment of his or her work is, a botch should not be accepted, nor paid for. And as far as assessments go, the repairer – an experienced repairer – can usually anticipate what the likely outcome will be before attempting a repair. In the case of the TVR owner, the windscreen is now potentially ruined, and the car may even fail its next MOT.

What does a ‘good’ repair look like?

The answer is quite simple. If, by looking at the windscreen, you can easily see the damage you shouldn’t be able to see it without looking for it once it has been repaired. This, however, is subjective to a few important factors:

  1. size;
  2. position on the windscreen;
  3. type of damage;
  4. the age of the chip (or how long it has been exposed to water and contaminants).

Ambient temperature, lighting, equipment, quality of consumable products and the experience of the technician are vitally important aspects which the repairer relies on in order to give prominence to his or her skill. The following image shows a common stone chip on a windscreen.

Chipped Windscreen

Damaged Windscreen

The chip is showing an impact crater (in the middle of the arc shape) and two smaller chips above it. There is one visible crack emanating from the centre of the impact point and threatening to travel southwest; the arc shape is often referred to as a ‘half moon’ although it almost has bears a resemblance to a ‘beeswing’. Underneath the arc shape are two more cracks: one feint crack perpendicular to the southwest pointing crack, and one dissecting the two smaller upper impacts. Placing a mirror behind the break adds clarity:

Mirror Behind Stonechip

Mirror Behind Stonechip

Using a mirror allows the technician to see how the break is responding as various repair techniques are utilised. These are carefully honed skills which enable the break to be manipulated in order to allow the repair resin to penetrate fully into each crack.

Windscreen After Repair

Windscreen After Repair

With the repair complete, and the apparatus removed, the above image shows what the (now repaired) damage looks like with a mirror reflecting light back through the glass. In technical terms (or optics) the light propagating through a medium (in this example, glass) has a refractive index or index of refraction: a dimensionless number which determines how much light is bent, or refracted, when entering a material. With the mirror removed light no longer reflects back through the glass:

Repaired Stone Chip with Mirror Removed

Repaired Stone Chip with Mirror Removed

As good as a repair can look when finished, there is no miraculous vanishing trick. There will always be at least some trace of the damage. This is usually the outline of the impact crater and some visible evidence of the bonded cracks:

A Shadow of its Former Self

A Shadow of its Former Self

It should be noted that whilst there is a mirror present, there is no smoke to trick you into looking elsewhere. Given the nature and definition of glass (it’s transparent!) resolution and focus will always be difficult to replicate from shot to shot when capturing images. A camera will passively focus on an area detected by the autofocus – or AF – sensor(s). The camera in all images was on a standard iPhone 6 device, and by placing it on a predetermined, X, Y and Z axis. The AF was allowed to detect what was in front of it, and the same three manual overrides were used before each image was taken. In no way was it an accurate science. These images were capture in a very basic exercise in order to illustrate the before and after of a windscreen stone chip repair.

As with all posts, comments and feedback welcomed, and gratefully received.

Insurance Questions: Windscreen Cover

 

 

Can I get my insurer to pay for this?

Most comprehensive insurance policies will include windscreen cover as standard. As straight forward as this may appear, there are some grey areas, some of which has been misinterpreted or misunderstood, to cause confusion amongst the insured.

 

Direct Vision through Windscreen

Direct Vision through Windscreen

 

Here are some of the most common questions asked on Internet forums; but first, it should be noted that the onus is very much on policyholder to tell the truth. The repairer’s role is a position of trust and one which requires him or her to make an assessment on behalf of the insurer/underwriter (as well as to present the policyholder the correct diagnosis). Honesty is always the best policy, but there are a few areas which are open to abuse.

 

“I bought a car which had a cracked windscreen,” or that the car had a chipped windscreen which has previously been repaired badly.

This is probably the most asked question, and almost definitely the one which shows the most ignorance and dishonesty among those who discuss it. The reality is, the damage occurred before (current) policy inception. It is not a loss the insurer is obliged to indemnify. The problem with this situation is that the insurer relies on the honesty of the policyholder, and the integrity of the repairer but there is no way of verifying the cause (and date) of the reported damage.

 

“My windscreen is scratched. Am I covered?”

 

A tricky one and very much subjective. How an insurer – or the insurance policy – interprets damage is how this one will be defined. Policy wording seldom identifies scratched glass as damage, although it could be argued that graffiti is vandalism but this may not be covered under the windscreen insurance end of the policy (some insurers have paid out for this under general insurance which will carry a higher excess and will impact the policyholder’s NCD). The only way to ascertain if wiper scratches or general scratches (such as from clearing ice or dirt from the windscreen) are covered by an insurer is to check the policy Key Facts or speak to the insurer. The problem this presents is that the ‘glassline’ number will usually be pointed straight at the prevailing repairer whose role is to make an honest and correct assessment on behalf of the insurer it is representing.

 

Pitted Windscreen 2

Pitted Windscreen

 

Pitted Glass

“There is surface pitting on my windscreen. When I’m driving into direct sunlight, or oncoming headlamps, I can’t see through the glass. It’s like the windscreen has been shot blasted and is covered with millions of tiny chips about the size of a pin head.”

 

First and foremost, the windscreen is a forward facing piece of glass in a vehicle. In other words, the driver’s direct view of the road is reliant on the windscreen being in good condition, or being fit for purpose. For vehicle to be legally roadworthy, the MOT Testers Manual states that a reason for rejection is:

“a combination of minor damage areas which seriously restricts the driver’s view in the remainder of the [wiper] swept area”

With this in mind, does this correlate and fit into what the insurer will construe as damage, or an indemnifiable loss? Some insurers will allow some discretion whilst others may not be so accommodating.  Most pertinent to note is that this is all open to interpretation whichever way you were to look at it and the system (in the absence of a better noun) is open to abuse by all parties.

 

“Will claiming on my insurance impact my NCD?”

Probably the most enigmatic and undefined areas of windscreen insurance is what subsequent impact a claim will have on any future insurance. The majority of policies will state that there will be no impact on NCD following a windscreen claim, however, some policies clearly do. Furthermore, there is no definitive statement from any insurer whether – regardless of how NCD may or may not be affected – the premium will be increased on renewal. Is there a claw-back somewhere? The nature of the business suggests there might be; is it a factor in the rising cost of motor insurance? There is no official word on this and insurance industry representatives remain reticent.

 

Windscreen Replacement

Windscreen Replacement

Have you had one of these windscreen claim experiences with your insurer? Please use the comments section to tell us all about it; your contribution may be useful to others. Thank you!

 

It’s Only a Joint?

 

 

 

When butting up the PUR adhesive, most windscreen fitters are taught to run past the starting point and overlap the joint. This technique envelops the join, and is the easiest one to program the OEM robots with. Is this the best way? Why does it matter?

Wide

Overlapped PUR Joint

This joint measured about 50mm in width, more than double the industry average. So what’s the issue? It’s a joint, and other than the somewhat abstract appearance, it looks like it ‘did the job’, right? Here’s what it looked like on the other side after cutting through it with a sharp blade:

FullSizeRenderTunnel

Tunneling

As you can see on the left hand side, there was very little adhesion; about 4mm in fact. The shiny bit to the right of the image is cured PUR which was not making any contact with anything. If it’s not making contact, it’s useless; superfluous. A waste of product material, and potentially a catalyst for a defect in the windscreen, or glass performance.

 

 

 

 

Paint it Black

 

 

A question often asked amongst motoring enthusiasts is, “I’m having my windscreen replaced today. Is there anything to look out for?” Generally, the advice will be pretty good, and mostly based on experience. However some responses are the work of fiction; a fallacy; an internet fable, see it here.

“Before the fitter puts the new windscreen in, make sure he paints over the scratches with that black primer!”

Porsche 991 Windscreen Removal

Paintwork scratched by windscreen fitter.

This statement highlights an important issue, and just how easily vital information can be grossly misinterpreted and misrepresented. Three of the most used aftermarket polyurethane bonding systems used in the automotive glass replacement ( “AGR” ) industry in the UK are Betaseal (Dow Automotive) Dinitrol and Sika. All three are also used by vehicle manufacturers on the assembly lines all over the world. From their respective websites:

Dinitrol 530.

“Black, solvent based physical and chemical drying primer designed to prepare the cleaned automotive glasses and the flange for direct glazing. DINITROL 530 promotes the adhesion of the polyurethane sealer to the substrates, but also prevents the degradation of the polyurethane due to Ultra Violet radiation.”

Betaseal 43532

“BETASEAL 43532 primer is recommended for use as an adhesion promoter between BETASEAL™ urethane adhesives and automotive paint coatings”

Sika 206 G+P

“Sika® Primer-206 G+P is used to give improved adhesion in adhesive bonding applications on sub-strates such as glass, ceramic-coated glass and painted surfaces. Sika® Primer-206 G+P can also be used on other substrates such as plastics and some metals.”

The product descriptions are condensed, and a fuller technical data sheet furnishes us with all the finer details, but notwithstanding, the single paragraphs – at a glance – tell you what you need to know. The common denominator in all three: black primer is an adhesion promoter. Applying it provides a suitable substrate to bond to. There is no mention of it being suitable for coating bare, or bared,  metal. The emphasis of its use – by its users – is largely misplaced, and anyone using black primer – adhesion promoter – to paint over scratches is missing the point: avoid scratching the paintwork to begin with. The long term damage can be very expensive and often does not manifest itself until the car has moved on to a new owner.

BMW E46 M3 Windscreen

BMW E46 M3 Windscreen Removed

None of us are exempt from making an innocent mistake, but when we do, we learn from it; we gain knowledge. Experience is knowing all the pitfalls of your trade and more importantly, how to avoid them. We don’t paint the mistakes black with primer. We consciously avoid making those blunders in the first place. The prevention is a critical part of eliminating the risk of corrosion. Like in the image of the BMW E46 M3 above, sometimes there is no excuse to scratch the pinchweld on removing the windscreen and there is no justification whatsoever for the pinchweld to be bared of its paint when cutting back the old Polyurethane ( “PUR” ). Steve Allard of Western Windscreens in Launceston shows us just how futile covering a scratch with black primer really is. The car: a Mercedes-Benz SLK had come into his workshop for a new windscreen. It should have been a routine replacement, but the job turned into much more when he found some scratches which had been hidden with something that was not designed to protect bare metal from oxidising.

Merc Windscreen

Picture courtesy of Western Winsdcreens in Launceston.

Nobody in their right mind could claim the car is a rot box as the metal around the scratch has not rusted, therefore negating the claim or suggestion. The black primer is clearly not sufficient, and does not inhibit the corrosion of the metal beneath the paint.

Merc Windshield

Image courtesy of Steve Allard, Western Windscreens, Cornwall

Black primer is not for painting scratches. Its use is for preparing a freshly painted surface to promote better adhesion; it is used to provide a better a substrate to bond to; it is not designed to be used as a rust inhibitor, or to ‘fill in’ scratched paintwork. Even accident, or crash repair centres can be guilty of thinking that the windscreen fitter’s black primer is some magical cure, and an excuse for the painter not to put in the effort:
Windscreen Fail

Unsuitable for bonding

A Porsche 996 (pictured above) had a new roof skin replaced prior to the windscreen being removed after it cracked on a track day. Cutting back the PUR revealed some pretty alarming evidence of what was supposed to be a repair by a Porsche ‘approved’ bodyshop. There was evidence of black primer under the PUR but it had not adhered to the metal at all, and just lifted off the pinchweld like the floating thin layer of brittle black primer that it was. There was no chemical bond between to the two materials.

Those who are engaging in such practices will not be around to witness the damage in time to come. The car may even have since exchanged hands, and thus voided any warranty however subjective it may appear to be in the circumstances. The perpetrators of such careless and shoddy workmanship cannot be held culpable for the consequential loss which will invariably have been caused by their negligence, and this is as much of a crime as the act itself.

Removing a windscreen, and cutting back the adhesive that held it in is easier today than it has ever been. There are a variety of removal apparatus and cutting implements readily available whilst finely honed techniques remain the most important tool of the fitter’s repertoire. Yet there are so many who neglect to use them or are ignorant to the fact. In some ways, the windscreen fitter skills and mindset has perpetuated its own paradox. Added to this is an incessant need for speed; there appears to be so much emphasis on cheaper, easier and quicker ways to get the job done. Not many have the time nor the inclination to do a good job, or take pride in their work.

Windscreen Replacement

Appropriate and correct treatment of bare metal

It is inevitable that at some point, you are going to bare some metal as you cut back old PUR. It might be a raised spot-weld, or it might be a slip with your chisel. Within reason, and after careful assessment, you may be justified in ‘dotting’ a small mark in the bondline with primer, but if you want to be thorough, and offer a guarantee which is as robust as the work you’re aiming to complete, or is in line with the car manufacturer’s warranty, you have to spend a little bit more time than just dabbing on something which is not fit for purpose. A little more application – literally – is in order.
Windscreen Replacement

Treating bared metal with a chemically bonding agent

 

 

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As always, comments most welcome, and ‘likes’ gratefully received. Thank you.