Remote Keyless Entry

Could be a couple of things. First what I would do is find out what brand it is, maybe look on the remote, or the inside of the remote. Find the model number and brand. You can usually look that stuff up online or call the companies tech support. It probably either blew a fuse or you need to reset it. Usually is on the unit itself. It helps to know where the unit box is. Under the dash or under the hood. It's usually a black box with a bunch of wires coming out of it. Good luck

It is a factory job, nothing major. Just sounds the horn. It is just part of the standard security system, and the ignition key has a security chip. Will there be a fuse for that also?

Does the alarm work still or is it just the keyless entry that is not working. Sometimes there is a button located usually under the stearing wheel area that is a reset button basically. Not sure of the procedure but sometimes you have to have the key in the door and press the button, sometimes the ignition. There is probably a combination of things. If the alarm works still it's not the fuse.I would take it into the dealer and ask them. Don't ask them to fix it, just have someone come out and look at it and see if it's a quick fix. Check for the button first. Under the driver side dash area.

Sometimes when the battery goes dead you might have to have it reprogrammed. Using the key in the door won't harm or disingage the keyless entry, it's made to use it both ways. You can take it to the dealer and they should reprogram it for free. It's takes 1 minute. Call them first.