EZ-Pass transponder mounting on refreshed nosecone-less Model S

[cdhowe]

I just got back from taking my one week old S90D from Massachusetts to Maine and back and discovered that my 11-year-old MA FastLane transponder (it predates the EZ-Pass transition) mounted in the black area of the windshield (no dots on the new windshield -- you get transparent or black) was read in NH, but not in Maine.

Figuring it was the battery, I brought it to the Boston EZ-Pass office today and asked for a replacement. They tested it and said that it works fine and therefore will not replace it with a new interior transponder -- only with the big black license plate one. Knowing the problems people have had with license plate mounts and autopilot hardware (my model S has that), and not having a nosecone to hide it in (I have a refreshed design model S), I've decided to keep my FastLane transponder and try the rear parcel shelf mounting, but given the age of the transponder and its batteries, I'm skeptical it's going to work.

I'll update when I've tried the new mounting with this ancient transponder, but a colleague here offered a good solution that I might consider if the parcel shelf mounting doesn't work: register with the Pennsylvania Turnpike to get one of their new interior EZ-Pass transponders. The claim is that they don't care if your plate is from out of state, and they would give me a more modern interior transponder.

in the meantime, I'd love to hear more stories of EZ-Pass mounting successes from owners of the new design model Ss.

 

[Cr8it]

I live in a gated community that uses transponders to open them. I have a P90D refreshed model. So far the only solution I have is opening the sunroof and holding the darn thing in the air. I share your interest in an answer to this one.

 

[Texas]

Surely there is some way to mount that ugly thing behind the fascia--which I assume is plastic. Talk to someone at your Service Center.

 

[artsci]

Surely there is some way to mount that ugly thing behind the fascia--which I assume is plastic. Talk to someone at your Service Center.

That likely won't work -- there's a lot of metal between the fascia and the front of the car which will likely block the signal.

 

[FloridaGary]

I had to replace my SunPass with the license plate transponder and a transponder that opens our gated sub-division. Fortunately, I have the nosecone and they work flawlessly. However, I have reserved a Model 3 to eventually replace my Model S and when I saw the front end, I have a feeling I'll be holding my transponder through the window to get into my subdivision unless Tesla changes the the type of windshield they are currently using on the S. I am also curious to see what others are saying with the refreshed front end.

 

[JD Foster]

I picked up my refreshed 90D the day before taking it on a 700+ mile trip from PA to SC. I used the EZ Pass fast lane once, and then tried the EZ Pass transponder in a normal toll lane to see if it would read. I have it mounted on the inside front windshield. It didn't read at all the second time. Lucky for me, I don't have a license plate right now- I only have the "Zero Emissions" plate on, because I have to wait 2 weeks to get my bill of sale to self register in Pa. So I don't expect any charges to make it my way... Looks like I'll also be holding it out of the sunroof or letting them trace my license (once I finally get it!).

 

[jzzsxm]

I use an EZ pass on my refreshed 90D and have had success. When sitting in the car, to the right of the rearview mirror, there's a black area of glass. Holding the EZPass up to that area results in it being read.

 

[cdhowe]

Thanks for all your responses to my query. Here are some quick responses and an update.

My initial experiment was exactly what jzzsxm suggested: I mounted the transponder in the black area to the left of the rear view mirror. The lack of response in that location is what started this thread -- the transponder could not be read at all there. Fortunately, the Maine Turnpike was happy to read my license plates and no fines have been accumulated.

I tried the parcel shelf mounting suggested previously on the way into Boston today, and got a 50% (i.e., 1 out of 2 reads) green light success rate, which is better than my success rate on the windshield. I've adjusted it again this morning for what I hope is better visibility to the transponder readers and will see what the response rate is on the way home.

Another possibility I may try is mounting it on the inside of the non-moving section of the glass panoramic sunroof. However, others have said that the parcel shelf mount actually gets a better success rate.

For those of you suggesting holding the transponder up through the sunroof, I did try that on the way to Maine and got no response. I really do think my 12-year-old transponder batteries are at least part of my specific problem (even if the Mass EZ-Pass folks say the transponder responds just fine in their testing box).

More data as I can collect it.

 

[ScotMaine]

I'm awaiting delivery of my new Model S 60D, and I will want to permanently mount my EZPass, too. Do you have one of the newer versions (quite narrow, about an inch and a half high), or one of the older models that was like three inches high? Good discussion to keep having!

 

[Jorell]

cdhowe, just caught your reference to the license plate mounted hardware interfering with autopilot - hadn't seen that before; is there a thread on that (i did search but didn't see one). I had thought folks put it behind the nosecone for appearance reasons but I'm not bothered by that; if it affects autopilot, then i am concerned. Interesting, had first close call with AP right after putting the license plate transponder in when AP was slow to brake for a car in front of us when they stopped quickly. Now wondering . . .

 

[Joules Verne]

I have the solution for you.

I have a refreshed MS, and you're right the blacked-out area DOES NOT WORK. Certainly not for me. My car as autopilot.

My daily commute involves the Mass Pike.
I also recently did the same drive as you, from MA to ME (portland) - went to see me some Whitesnake!
Anyway.

I've been experimenting with different locations, and checking in with the EzPass service center weekly to see how things are tracking. They know me at this point.

I refuse to use the plate mounted abomination.

I'm using the newer transponder (smaller, rectangular one), and I place it in the back hatch under the divider (out of sight). The velcro on the transponder secures itself to the carpet.

See photo.

With the Pike, the transponder works flawlessly.
When traveling to/from ME, the transponder didn't work, but the ezpass camera system did, and I was charged properly ($4 each way).

Note: don't let the traffic status lights at the booth fool you. They will not be accurate, because the transponder signal triggers after you pass.

So I found a reliable placement.

 

[JPP]

...or if you are concerned because you remove your parcel shelf from time to time, then do what I did on my wife's 2015 S70D: mount it at the bottom center of the rear lift gate window. It is hidden from view in the inside rear mirror by the tall center headrest on the rear seats. To minimize ugliness, I wrapped the transponder in black vinyl electrical tape and used black Velcro on the window. YMMV.

 

[Soundchasr]

I have mine mounted on the black spot to the right of the mirror. No problems in PA but for some reason I got no joy in Ohio.

 

[Joules Verne]

...or if you are concerned because you remove your parcel shelf from time to time, then do what I did on my wife's 2015 S70D: mount it at the bottom center of the rear lift gate window. It is hidden from view in the inside rear mirror by the tall center headrest on the rear seats. To minimize ugliness, I wrapped the transponder in black vinyl electrical tape and used black Velcro on the window. YMMV.

That's a good idea.

 

[cdhowe]

Wow, you guys are awesome. Thanks for sharing your experiences and reassuring me that the problem is not impossible to solve.

For those of you suggesting holding the transponder up through the sunroof, I did try that on the way to Maine and got no response. I really do think my 12-year-old transponder batteries are at least part of my specific problem (even if the Mass EZ-Pass folks say the transponder responds just fine in their testing box). However, until the transponder fails their test, they won't replace it with another internal transponder, only the license-plate mounted version (aka, the black abomination).

I tried the parcel shelf mounting suggested previously on the way into Boston this week, and got a 50% (i.e., 1 out of 2 reads) green light success rate, which is better than my success rate on the windshield.

What I have been doing lately is checking my EZ-Pass account the day after any toll activity. I have been worried by the toll lights that either didn't light at all or said to "Call EZ-Pass". What I've found is that when I had the transponder on the windshield, I was in fact having the transponder read. When it was mounted on the parcel shelf, however, the system is falling back to the license plate read (a V-Toll), which incurs and administration fee.

My plan on Saturday is to drive down the Pike to the Natick EZ-Pass center and have them check the transponder performance (and I hope the battery strength) again. That will allow me to point at the V-Toll complaints and see if they will give me a transponder with a battery from this decade.

As an electrical engineer and ham radio guy, I believe that if we gather enough data on the problem, we'll be able to engineer a solution. I appreciate everyone who has taken the time to add their successes and failures to the data set. I'll post again when I have any new information.

 

[Joules Verne]

I tried the parcel shelf mounting suggested previously on the way into Boston this week, and got a 50% (i.e., 1 out of 2 reads) green light success rate, which is better than my success rate on the windshield.

The status lights at the booth will be inaccurate.
I get a green light half the time as well.
However, when checking the transaction log at the EZPass service center, it worked 100%.

My plan on Saturday is to drive down the Pike to the Natick EZ-Pass center and have them check the transponder performance (and I hope the battery strength) again. That will allow me to point at the V-Toll complaints and see if they will give me a transponder with a battery from this decade.

The day I got my MS, I went to the Natick EZpass center (eastbound), and swapped-out my old transponder (square) with the new (smaller rectangular).

I just said I need the smaller form factor to fit the designated windshield location.
They swapped it without any trouble.

 

[Joules Verne]

However, when checking the transaction log at the EZPass service center, it worked 100%.

Great Scott!! Spoke too soon.
Just checked the logs, and it didn't register at entry yesterday.

I'm going to try JPPs technique.

What a PITA.

 

[meeb]

Having the same issues. I have an old large PA EZ Pass, and getting about 50% green light, even when going reaaaalll slow from PA up to Boston & back. Started opening the sunroof while trying to hold it in the right orientation, I think that seemed to slightly increase reliability but isn't much of a permanent solution. Now I have 4 charges (and counting) to dispute because it only grabbed the entrance and not the exit. Like JD Foster I have to wait for my plate and EZ Pass is getting a bunch of pictures of my "Zero Emissions" plate!

In the land of no front plates, I'm not willing to put the exterior transponder on! I'll try the rear window and maybe try exchanging for a newer, smaller transponder.

 

[JD Foster]

Well I now have a license plate, so I am "on the grid"- trackable if the EZ Pass doesn't read. I tried putting the EZ Pass in the black spot to the right of the rear view mirror, but this was unsuccessful for me. I came to a complete stop and it still didn't read (I was at the combined EZ Pass/Ticket lane).

Holding it out of the sunroof did work, but I felt like and idiot and really would rather not do this when it is raining.

I am going to try Joules Verne's location under the parcel shelf. Hopefully that works out!

 

[murphyS90D]

I really do think my 12-year-old transponder batteries are at least part of my specific problem (even if the Mass EZ-Pass folks say the transponder responds just fine in their testing box). However, until the transponder fails their test, they won't replace it with another internal transponder, only the license-plate mounted version (aka, the black abomination).

The shelf life of most batteries is 10 years. With 12 years of use I'm surprised it has any output at all. When my old square PA transponder got to be 10 years old I told the PA E-ZPass center I wanted a new one. They shipped one out and I returned the old one. The new one is much smaller and rectangular. On a trip to VA in May it worked at all tolls where the speed limit is 30 mph or higher. It failed at all tolls where the speed limit is 15 mph or lower. I changed the mounting position to be about one inch below the top of the windshield and mounted vertically with the top to the left. It works on both low and high speed tolls on the PA Turnpike. I won't know about DE and MD until November.