I recently had a battery go out in a key fob that came with my HSE when I bought the truck in January 2021. Given the low price of replacement fobs with a new circuit board and battery, it was easier and faster for me to order the replacement, put the new board into the old case with the existing cut blade, and then reprogram all of my keys with my GAP tool. The process was made easier because it looks like what I call my primary key from the original owner is the product of a non-OEM fob with an old blade swapped into the rotating blade holder through a pin transplant. The non-OEM ones I've seen all have a screw holding the two halves of the fob together for easy splitting and rebuilding. Such genius....

What was interesting was the fact the vehicle's info display started warning me about a low fob battery prior to it failing altogether. The manual says that using the key to start the engine and running the vehicle "will start to recharge the remote control battery." I wasn't upset when the fail happened...I've been using the fob for five years and it could have been years before then that the fob had a new battery, so that's a pretty good stretch of time for a replacement is needed.

But what I don't understand is how inserting the blade into the ignition switch and running the engine could recharge the fob battery. I've opened up a few of these fobs to build up a supply of spare keys and from what I could see, there's nothing obvious on the blade that could act as separate positive and negative DC paths. And even if there were, the blade in this fob is only connected to a rotating blade holder that doesn't seem to have any contact with the circuit board. Unless some sort of induction charging is involved, which would be heady stuff for a 2006 vehicle, I'm wondering if the non-OEM key fobs differ from the official LR versions not only in regard to price and joining screw, but also in having a working ignition-switch-to-fob-circuit-connection that the knockoffs lack.

Any insight into this?

Nick in Palm Springs

 

There is a coil in the steering wheel that transmits a wireless current to the key fob. Wireless charging before wireless was cool! I believe it's also the antenna to recieve the sginal from the key that allows you to start.

It looks like the sort of antenna as in a BMW X3, and if you manage to let the wires get loose they will turn your interior into a fairyland of fine copper wire.

 

Induction charging. The cheap fobs usually lack the circuit tho so the batteries do not last nearly as long. Also if you have an original OEM fob and replace the battery, must be the correct rechargeable version.

 

Ahhhh... Not sure if the old one had induction capability as it was clearly non-OEM, though the battery was labeled as an LIR-2032 rechargeable. Either way, I got five full years of service out of it and maybe much more depending on when the P.O. received it as a replacement.

Thanks for clearing that up!

Nick in Palm Spring