Pulled into car wash, disconnected negative from main battery within a couple of minutes. Washed the car and engine bay. Returned to car and "smart key not found" and could only start it by holding the key under the steering column with RFD bypass.

According to a Land Rover dealer service tech, disconnecting the battery within a couple of minutes of turning off the LR4 may have caused the key fob to be deactivated.

Took smart key to battery shop, they said it was dead, replaced battery, confirmed it is transmitting with their test and still received the "smart key not found" error.

Disconnected fuse #17 inside glove box per the advice on other threads for a few minutes. Didn't resolve. Then tried disconnecting both batteries for 10 minutes to try to reset the system. Didn't resolve. Then tried a hard reset by disconnecting both batteries and touching positive and negative together for a minute. Problem persists.

The previous owner finally found the second original key fob and I will have that in one day. I've read that "if the vehicle is locked by another key, or if keyless locking arms the alarm. Keys become deactivated if left inside the vehicle when closing the tailgate, bootlid or taildoor while the alarm is armed. To reactivate a key: Start the vehicle using another activated smart key" on the Land Rover website, but that's for the 2021 Defender.

If that doesn't work, Land Rover said they could try to reprogram the key for $185 (hour shop fee).

Is it possible to program a smart key for a 2016 with the iLand tool or Gap IID tool? If yes, I'll put the $185 toward the purchase of one of those diagnostic tools.

Thanks.