Help please! Unlocking and locking my car via the remote largely stopped working (with my main key and the spare). I took the car to the repair shop, and after driving 20 min, the remote worked fine. They checked the computer to see if failures had registered (they had) and told me I’d likely have to replace the part in the door (pricey!) if the problem persisted. It has. The remote won’t work at all, and then after I drive the car for a while, it works (as if it is somehow being recharged by driving.) I phoned my repair guy again, and he’s mystified, cannot explain how driving for a period of time makes the key remote work.
Just a thought, but have you ever replaced the battery in the key fob? Autozone and a couple of other auto parts stores sometimes have a neat tester by Energizer that can sense if your key fob is working by lighting an LED. My Ford turned about 10-11 years old, and both fobs started working intermittently like that. New batteries fixed them.
A weak battery will make the remote give off a weak signal. That weak signal will behave strangely, and can be interfered with under certain conditions. Change the battery first. It’s cheap and easy to do.
Hopefully it is a problem in the key fob. I had one acting up, and found a lot of green corrosion. I settled on replacing it. If the key fob itself cannot be shown to be acting up, the receiver in the car must be, and it will not be cheap. The receiver is probably part of the security module and requires the dealer to program a replacement to work.
The key fobs do not seem to be the issue because both I have behave identically. They think it’s the part in the door, but why would it work after I drive at least a 1/2 hour? That is the question I have.
Assuming the FOBs are both the same age, perhaps they both could use a new battery. The batteries are available anywhere. They’re just coin-shaped regular lithium-ion batteries. Your owner’s manual will tell you how to change it. By the way, 10 years is a pretty fair life for these batteries.