I have changed the coin battery in both of my Smart Keys but every time I get in the car to start it, I'm getting the message that the key isn't present. This has happened when the key is in the right pocket of my cargo shorts and it has happened when the key is in my left pocket. The car won't start until I take the key out of my pocket and move it over towards the lower left hand side of the dash. At first I suspected the coin battery in the keys, but even with new batteries I'm getting that message and refusal to start and it getting to be a pain in the neck. Any suggestions?

 

Are you sure you are using new batteries and not just old ones that haven't been opened yet
I guess if it is happening to both smart keys it is probably the car.
Just make sure you are trying with just one key in the car at a time. Sometimes second key can cause interference so leave it in the house whilst you are troubleshooting.
After getting in the car and closing the door try locking and then unlocking the car with the key fob first before trying to start the car.
If all this fails then maybe you have a faulty keyless vehicle module

 

That is one of my issues, have not solved. Wondering if you're having any of my other issues-
https://www.jaguarforums.com/forum/f...-issue-249702/

 

Make sure your cell phone is not in the same pocket or near the pocket with the key. Cell phone RF can interfere with/block the signals from the key fob because they have more power.

 

I find that perplexing since I also have a 2018 Jeep Wrangler and my wife has a 2017 Cadillac XT5 and I have zero RF issues with my iPhone and those key-less entry/start keys.

 

Different manufacturers implement different antenna configurations inside and outside the car. Some have multiple antennas, others only have one. Not saying this is the cause, but in your troubleshooting you should eliminate this as a possible source of interference.

 

Fob antenna locations…
https://www.dropbox.com/s/m5n0e5yn82...0vert.JPG?dl=0

 

I think I figured out my Smart Key issue, lets just calling it a user error. Given that I have two keys for the Jag, I always keep the spare key in my metal tool box in the garage so that I can pull the cars in or out depending on what work I need to do on them without running back into the house to retrieve the "other" key. I hadn't actually gotten around to putting the extra key into the tool box that I suspect would have acted like a Faraday cage, instead it was sitting on a wooden box right next to the passenger side of the car. When I realized that the spare key might be causing interference, I took it inside the house and have tried starting the car multiple times with the key in various pockets and near my iPhone and wallet with a metal credit car in it and the car starts every time. I've even tried both keys, with the other securely in the house and away from the car with equal success. Next I have to try securing the spare key in the metal tool box and see if I get the same positive outcome.

 

That's interesting, I always drive with both fobs in my pockets (one in each pocket) and have never had any problems (flat batteries notwithstanding!).

 

When I bought the car, I had both keys in my pockets with no issue too. I think having one key outside the car right next to the passenger door (literally 18 inches away) and another in the car confused the antenna setup.

 

Why would you drive with 2 key fobs, one in each pocket?

 

One's on my house keyring, the other is in case I lose them. I always take two keys with me, just in case (or in pocket).

 

What if you lose your pants?

 

That doesn't bare thinking about!

 

I keep my fob in a faraday box in my safe. Probably overkill. I'm trying to get extra fobs from the dealership since I only have one.