Hmm, not behind the rear-view pillar then (effectively behind the mirror itself)? That's what I was going to try.
Coated windshield impacting door openers and EZpass
- Thread starter cinergi
- Start date
-
- Tags
- Model S User Interface
Hmm, not behind the rear-view pillar then (effectively behind the mirror itself)? That's what I was going to try.
Newscutter
Member
We move our EZPass from car to car as well and usually just hold it up to the glass in our other cars as we go through.
Curious: could the transponder just be held up to the pano roof glass instead-- just skip the windshield tricks altogether?
Curious: could the transponder just be held up to the pano roof glass instead-- just skip the windshield tricks altogether?
mknox
Well-Known Member
apvbguy
Banned
FWIW: I meet a fellow at the newark DE sc who had his ezpass mounted directly behind his rearview mirror and he claimed that it worked well for him.
YMMV
YMMV
I asked for the plate mounted transponder. Not taking any chances. In Mass, we are required to have a front plate as well.
HankLloydRight
No Roads
I'm not telling you to do it, but I ran with no front plates on my cars in MA for many years and didn't have any problems/tickets. YMMV. Also, I feel the front plate destroys the look of the beautiful Model S. So I'm willing to run the risk and pay a $25 every other year, if/when that happens (and it never has for me), in exchange for not mounting a front plate. But that's just me.
It also goes through the side windows, which isn't useful for EZPass (or equivalent), but is useful for my gated community.
mknox
Well-Known Member
Fair enough. I tried my highway transponder through the side glass, but the angle was wrong to reach the overhead gantry as I drove through. I've been having some success with just leaving the transponder on top of my rear cargo shelf and it seems to get through the back window. Maybe 8 out of 10 times.
darthvdr
Member
Nowadays, I just open the window and hold it out. Not the best way as I almost dropped my transponder once.
mknox
Well-Known Member
I live in a gated community in Scottsdale. The window sticker gate opener would not work anywhere on the glass. I had to obtain the ugly black bar to obtain entry. My service center in Scottsdale attached it behind the nose one completely out of sight and it works perfectly.
I drive in So Cal and have a transponder for the toll roads here. I put the transponder by the rear view mirror. To the right (passenger side) side of the mirror. I put it as high and as close to the mirror as I can. It has worked fine since then.
Its important to note that we are talking about two different items here. EZPass boxes are Active transponder systems, analogous to Active RFID systems. These use self-powered RFID tags that continuously broadcast their own signal using a permanently sealed lithium battery. Active tags provide a much longer read range than passive tags, but they are also much more expensive, which is why passive RFID systems have become more popular.
The Peach Pass is a Passive RFID system, which use tags that are powered by the electromagnetic energy transmitted from an RFID reader. In other words, the tag on your windshield has no battery, and instead converts the EM energy received through its antenna to electrical energy to transmit the RFID signal back to the RFID reader. Because the RFID chip receives power through its antenna, the antenna orientation is important. Mounting the tag in the orientation recommended by the supplier is critical in effective reading. For a Peach Pass, that means mount it horizontally, no matter where you mount it (hold the pass up to a light…you can see the antenna). It may work in orientations other than those recommended, but the range will be reduced.
The Peach Pass is a Passive RFID system, which use tags that are powered by the electromagnetic energy transmitted from an RFID reader. In other words, the tag on your windshield has no battery, and instead converts the EM energy received through its antenna to electrical energy to transmit the RFID signal back to the RFID reader. Because the RFID chip receives power through its antenna, the antenna orientation is important. Mounting the tag in the orientation recommended by the supplier is critical in effective reading. For a Peach Pass, that means mount it horizontally, no matter where you mount it (hold the pass up to a light…you can see the antenna). It may work in orientations other than those recommended, but the range will be reduced.
HankLloydRight
No Roads
I don't believe they are continuously broadcasting their RFID signal, but rather they are listening for, and respond to a 915 mhz signal sent from the toll booth antenna which triggers the EZPass to transmit it's account information back to the toll booth antenna. Sort of a passive+active system.
Thats may be correct. Continuous transmission is unlikely...but they are self powered which probably makes them less dependent on antenna orientation.
rxlawdude
Active Member
Regardless of passive or active technology, at least for recent MS builds, the area immediately to the right of the autopilot camera (solid black area of glass) is the only place that passes RF reliably. But the if the antenna of the device is not oriented exactly to be in that "sweet spot," it won't work. The Southern California TCA FastTrak transponder, for example, is reported not to work well; I've found that orienting it is critical, and that's probably why people who just hold it near the windshield in that area still are finding it not working. But there will always be an orientation that works. It just takes some trial and error for your particular variant of these transponders.
I do understand that some production runs of the MS had windshields with "dots" in this upper area that didn't pass RF no matter what. This seems to have been resolved in newer VINs.
travwill
Active Member
Yeah, I have a end May/early June build 70D. Only black dots in a thin line around top of windshield and not much if any black area by camera. My work garage passive transponder does not work anywhere, tried it exhaustively for several minutes in just about every position. Sucks! Every day I have to now open the sunroof and hold it up or role down the window and reach way around outside towards center of windshield as much as possible. Not a huge pain but it will be more when its snowing/cold/etc.
JPP
Active Member
Mount your transponder (FasTrak, EZPass, work gate unit, etc) behind the nose cone. if you can, get an exterior/license plate unit. If not, seal up the unit with Plastidip. Use heavy duty Velcro). Mount to the back of the nose cone if the unit is light plastic. Mount to the front of the black bumper (and add a zip tie) if it is heavy. Works for me. Please search these forums for way too many options/opinions. And, yes, neither my 2013 nor my wife's 2015 S have a 'sweet spot' in the windshield that works with the FasTrak.
