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Warning to model S owners in Colorado.

gfs

Member
May 21, 2010
15
10
colorado
I36 & I25 in Denver has a new switchable transponder for the HOV/toll lane.
I put one on the windshield of my S. I just got my first statement and their system did not see the transponder and billed me via license plate (even though I was HOV).
I called and they said that Tesla windshields have some sort of coating that prevents them from seeing the signal from the transponder, so I have to call and get a refund each month until they 'figure it out'.
At first they blamed it on it being an electric car, then they finally agreed that had nothing to do with it and it was a windshield issue.
I can't imagine what is so special about Tesla windshield that other high-end cars don't do.
 

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
I36 & I25 in Denver has a new switchable transponder for the HOV/toll lane.
I put one on the windshield of my S. I just got my first statement and their system did not see the transponder and billed me via license plate (even though I was HOV).
I called and they said that Tesla windshields have some sort of coating that prevents them from seeing the signal from the transponder, so I have to call and get a refund each month until they 'figure it out'.
At first they blamed it on it being an electric car, then they finally agreed that had nothing to do with it and it was a windshield issue.
I can't imagine what is so special about Tesla windshield that other high-end cars don't do.

This is a fairly common issue (there's a few threads on it). There's something up with the windshield in the Model S that causes this with various transponders. I now have mine mounted in the lower air dam/grille, but it still only reads sometimes.
 

MichaelS

Supporting Member
Supporting Member
Aug 8, 2012
320
51
Hayward CA
Update

There is some kind of metalized coating in between the glass layers that blocks the RF. There are many threads on this, look for Fastpass and Easypass. Dashcams with GPS also have a problem in that location.

The best solution I found is to mount the transponder under the nosecone in the front of the car. Works great.

I just saw you have a switchable transponder. That makes it tougher. In California we use Fastrak.
 
Last edited:

MrClown

Autosteer Beta Tester
Oct 3, 2014
222
46
Denver
Some people have had luck putting the transponder at the top of the windshield up against the right side of the rear-view mirror mount point. That has not worked for me. If that doesn't work for you, you may have to just hold it out the window when needed.
 

travwill

Active Member
May 1, 2015
1,729
1,222
Marble Falls, TX
I36 & I25 in Denver has a new switchable transponder for the HOV/toll lane.
I put one on the windshield of my S. I just got my first statement and their system did not see the transponder and billed me via license plate (even though I was HOV).
I called and they said that Tesla windshields have some sort of coating that prevents them from seeing the signal from the transponder, so I have to call and get a refund each month until they 'figure it out'.
At first they blamed it on it being an electric car, then they finally agreed that had nothing to do with it and it was a windshield issue.
I can't imagine what is so special about Tesla windshield that other high-end cars don't do.

Yeah, this isn't new. If you have a very new build, July forward, you may have the new large black area to the right of your mirror where you can place the trasnponder. Otherwise, if you don't, like me, you are best getting the license plate mountable version of transponder if you guys use front plates. If you don't, then you can mount directly behind the nosecose plastic (works best though with the larger plate transponder still).

Our other Range Rover has the same windshield that is also heated and it also has a clear space where it isn't coated that you can put a transponder - Tesla forgot this for a while. :-/
 

Only Trons

Supporting Member
Supporting Member
Jun 22, 2013
497
512
Northern Virginia
There are several (I believe) threads on this issue. A friend of mine with a Sig S had no problems initially, and then when his windshield was replaced (a year or so ago?) the EZ Pass transponder could not be read anymore, so he had to resort to the license plate mounted transponder. Unfortunately that doesn't work (here) for those who need a switchable transponder. In my MS (delivered 4/2013), I put my transponder in the area just above and to the right of the rear view mirror and it has worked perfectly.
 

riptide87

Member
Mar 31, 2015
7
0
United States
I36 & I25 in Denver has a new switchable transponder for the HOV/toll lane.
I put one on the windshield of my S. I just got my first statement and their system did not see the transponder and billed me via license plate (even though I was HOV).
I called and they said that Tesla windshields have some sort of coating that prevents them from seeing the signal from the transponder, so I have to call and get a refund each month until they 'figure it out'.
At first they blamed it on it being an electric car, then they finally agreed that had nothing to do with it and it was a windshield issue.
I can't imagine what is so special about Tesla windshield that other high-end cars don't do.

I'm in Colorado and drive GoPass / W-470 almost every day. They gave me a sticker transponder with instructions specific to the Tesla Model S to mount it inside on the middle of the windshield on a spot on top of the autopilot front-facing camera hardware. Apparently there is a gap in the shielding there. I followed the instructions and have not had a problem. I'll send you a picture if you want. Hope that helps.
 

stephenpace

VIN S00219
Dec 22, 2011
609
66
Houston, TX
I have a bar mounted transponder mounted behind the nosecone. However, if that option doesn't work for you, the Dallas service center has a nice solution of mounting it on the OUTSIDE of the windshield covered by a black vinyl cover. Sounds strange, but you can barely see it unless you are looking for it. More importantly, people that might want to steal it won't know what it is either.
 

Andyw2100

Well-Known Member
Oct 22, 2014
6,542
2,393
Ithaca, NY
For everyone who was suggesting the OP mount the transponder outside the car: he said he had a switchable transponder. I believe this means he has to manually change settings on it based on either the number of people in the car or the time of day or some other parameters. Having it outside the car won't work for him.
 

Blu Zap

Grinning member
Oct 1, 2014
1,094
708
San Rafael, CA.
Yes, mount the transponder on the windshield at the very top to the right of the rearview mirror. Works great now that I moved it up to the very top of the windshield.
 

Max*

Charging
Apr 8, 2015
6,672
3,719
NoVa
VA has a switchable transponder too for HOV. I couldn't get it to work anywhere on the inside (my windshield doesn't have the black cutout).

I got a plate mounted transponder and need to call 30 minutes before using the HOV lanes. But I can nominate my car for HOV for a week at a time. It's a bit of a PITA, but it works.
 

scottreds2k

Member
May 26, 2015
66
26
Silver Spring, MD
My 85D was delivered in June. Tesla apparently made a change to the windshield in May and now there is an uncoated area to the right of the rear view at the top that is the place to put the transponder inside the car. I just checked my EZPass bill and there are no charges by tag, only by transponder, so it seems to work there. When I took delivery, the DS noted that it was the 1st time he had seen that change.

20150911_090412.jpg
 

MrClown

Autosteer Beta Tester
Oct 3, 2014
222
46
Denver
My 85D was delivered in June. Tesla apparently made a change to the windshield in May and now there is an uncoated area to the right of the rear view at the top that is the place to put the transponder inside the car. I just checked my EZPass bill and there are no charges by tag, only by transponder, so it seems to work there. When I took delivery, the DS noted that it was the 1st time he had seen that change.

My 85D from March definitely doesn't have that area. Would have been nice. It'll be something to look forward to when the windshield needs to be replaced after a few I-70 winters.
 

naylee

Member
Mar 21, 2015
8
0
Fort Collins, CO
E470 warmed me about this too when I called to get a new transponder sticker. I was given verbal instructions over the phone and mounted as instructed. I recently used to go to the airport... I might give them a call today to see if it worked..

Denver Tesla center said I could try putting it on the bottom of left headlight.. which I didn't want to do haha.
 

mikeash

Active Member
Oct 26, 2014
1,105
703
Fairfax, VA, USA
VA has a switchable transponder too for HOV. I couldn't get it to work anywhere on the inside (my windshield doesn't have the black cutout).

I got a plate mounted transponder and need to call 30 minutes before using the HOV lanes. But I can nominate my car for HOV for a week at a time. It's a bit of a PITA, but it works.

Interesting, I'm in VA too and I was wondering what the deal was with that. I haven't bothered with the HOV stuff since I switched transponders, but it might be nice to save some money. Is it an automated system, or do you have to actually talk to people? What happens if, say, it turns out that one of your passengers can't make it?
 

Max*

Charging
Apr 8, 2015
6,672
3,719
NoVa
Interesting, I'm in VA too and I was wondering what the deal was with that. I haven't bothered with the HOV stuff since I switched transponders, but it might be nice to save some money. Is it an automated system, or do you have to actually talk to people? What happens if, say, it turns out that one of your passengers can't make it?

1. You need to call and talk to an actual person.
2. You need to give them your transponder number and account number each time (I made them put my transponder number in their notes section, so I don't have to tell them every time what it is, but that took some talking to)
3. They are only open from 7am-7pm Monday-Friday. So if you want to have a surprise trip on the HOV lanes, you need to play WAY ahead.
4. You need to give them at least a 30 minute notice before using the transponder.
5. You can set it up for up-to a week at a time (i.e. Monday-Sunday), but you can't permanently nominate the bumper tag to be HOV

I was so pissed, I even emailed transunion headquarters. Its' 2015!!!! Get with the game people! Let me log into a website and click a button. Or better yet, how about an APP! That would solve ALL the problems.

And if a person doesn't make it, you need to call 30 minutes before your trip, and tell them to turn off FLEX. Or risk getting a ticket from the cops who like to pull you off if they assume you have less than 3 people in the car and are in FLEX mode.


Overall a very crappy implementation, but when I was taking my kids to summer camp, I always had 3 people in the car, so I called them and set it up for a week at a time. Now? I mostly just avoid using it, because it's a PITA call them and sometimes wait on hold for up to 15mins (usually no wait though)

/vent
 

mikeash

Active Member
Oct 26, 2014
1,105
703
Fairfax, VA, USA
Overall a very crappy implementation, but when I was taking my kids to summer camp, I always had 3 people in the car, so I called them and set it up for a week at a time. Now? I mostly just avoid using it, because it's a PITA call them and sometimes wait on hold for up to 15mins (usually no wait though)

Thanks a lot for the info! Doesn't sound like it's worth it for me, but it's still good to know that for sure.

And yeah, why isn't there an app? So very silly. Well, I guess they have no real incentive to make this easier on us, because they don't exactly profit off us when we're in HOV mode.
 

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