Anyone else having problems with EZ Pass sensing in California

Anyone else having problems with EZ Pass sensing in California

I have used four different EZPASS devices in my car, and they all failed to regester at the Toll Both, though they worked flawlessly in my other cars. Has anyone else in California experienced this problem? It appears that the Model S is shielded to a degree that inhibits the EZPass signal. The last 2 devices were brand new ones I reveived in the past two weeks.

CC | March 7, 2013

First make sure your temp license or license is registered to the EZ pass.

Some people have success putting the EZpass just to the right of the rear view mirror in the area with the black dots.. But results very..

I haven't had the chance to try it out after i register my temp plate, and new Ez pass tag..

cosmomusic | March 7, 2013

I am regestered with my permanent plate.I was told by the EZPass folks that it is not a problem for me, as my license plate will be photograpged each time I pass through the Toll Booth and connection is not made with my device. They will then charge the fee to my account. So, as a practical matter it does not appears to be a problem, but I was quite curious as to the mechanism involved here.

bobinfla | March 7, 2013

@cosmo: Don't know if this applies in California or not, but had the same issues with our Sunpass in Florida. Found out that Sunpass has an external mountable pass that's meant to affix to the front license plate holder. I got one and Tampa service center popped the nosecone off, drilled two holes and mounted it underneath for me. Works like a charm and I love having it invisible. I didn't know the external mount passes existed until another Floridian posted something at TMC, so might be worth calling EZpass and seeing if they have such a thing too. | March 7, 2013

I had to go with the motorcycle version of EZ pass-- It's clear and mounts at the bottom of the front headlight

CC | March 7, 2013


Yes, the toll is able to take picture of your plate and charge to the account. But before I registered the temp plate, I even open the pano roof and stick the EZ pass outside the car, and it didn't work..

When I called, the EZ pass rep told me I need to registered the Temp plate to the account as well. | March 7, 2013

This may help (from search)

cosmomusic | March 7, 2013

Thanks for above discussions and link from This is clearly a problem which will be with us for sometime. Seems it will be different solutions for different locals. I will keep trying to find sweet spot.

Captain_Zap | March 7, 2013

I'd suggest that you post in the California threads to help your neighbors. Posts are less likely to get buried there. We have lots of local issues addressed in our state club threads.

andrea.elwork | March 8, 2013

I'm amazed at how much misinformation there is on this issue!

Tesla windshields do have uv protection that interferes with clear EZ Pass signals. No matter where you place the transmitter, sometimes it will register and sometimes it won't. Cars like the Mercedes S Class have built in square spots on the windshields where there is no uv protection- made specifically for toll transmitters like EZ Pass. The Model S has no such spots - the engineers forgot to build them in apparently. The customer service folks at Tesla have no clue about any of this and are giving customers all sorts of inconsistent misinformation on where to place the EZ pass like transmitters. in reality, there is no spot on the windshield designed just for these transmitters. The leaders at Tesla are either not aware of the probem, or are refusing to admit to it for fear of bad publicity. I wish they would pay greater attention to the aggravation that thousands of model S owners are going through with their toll collection transmitters and either tell us the truth or fix the problem.

The notion that the EZ Pass people will not penalize their customers for faulty readings is simoly false. Take a careful look at your list of monthly transactions and you will see all sorts of extra charges for improper readings.

The NJ EZ Pass people are currently investigating my case. They've not heard of Tesla and don't have it on their list of cars. I've asked for an outside transmitter and they are looking into my case to decide whether I should get one. In the meantime, i have to open my window each time i go through a toll area and stick out my arm with the EZ pass transmitter in my hand-,rain or snow, busiess suit or not.

Mark Z | March 12, 2013

Great news. A new transponder location was discovered that is working 100% of the time so far, even on the 91 Express Lanes that don't read as well as The Toll Roads.

It is under the rear hatch beneath the window in the plastic recess. It is hidden from view, but is angled correctly toward the electronic scanners and is located under the rear window glass. It is very easy to access when the rear hatch is open. This will help those who use the new 1-3 passenger transponders.

This is working with the battery operated FasTrak. The newer window based RFID type stickers are a different type and usually need to be mounted on the glass.

Now if only there was a sticker for the windshield to let the Highway Patrol know a transponder is installed.

Mark Z | March 14, 2013

The mirror mount location WORKS PERFECTLY. Here is a photo:

I received a response from "The Toll Roads" today. Please DISREGARD MY SUGGESTION of the rear hatch location. While it works and it's not on the glass, the Highway Patrol could be upset. Here is the reply:

"Thank you for contacting The Toll Roads.

In accordance with the California Vehicle Code, it is not permitted to place the transponder in the rear window.

The internal transponder may be placed on the lower left-hand side or right-hand side of your windshield or behind the rear view mirror where it will not obstruct your sight while driving.

At times, we have found that the polarized windshields have prevented the internal transponder from reading at all times. Therefore, it may be necessary to replace your internal transponder with an external one.

This recommendation is presented in situations when the internal transponder fails to read while properly mounted and generates a significant number of tolls which are paid by the license plate number instead of the transponder number.

The external transponders mount directly to the front license plate brackets and are secured with tamper-resistant screws. A special tool is provided in order to remove/affix the external transponder."

cosmomusic | March 14, 2013

I have ordered the external transponder which should arrive any day now. I was also told that is tamper resistant and works every time. This should solve the problems in California. I don't know if other States provide external transponders as well.

JZ13 | March 15, 2013

hmmmmm.....what to do if I did not have the front plate mount installed?

edcalis | March 15, 2013

The sixty five-trillion question.

P4768 | March 15, 2013

I put my external transponder under the nose cone.

Popped off the nose cone, velcroed it to the steel cross beam and put the cone back on.

No problems with being detected going through the Bay Bridge toll.