It has happened a couple of times only for no apparent reason. I press on the remote to lock the doors and I just get a long beeeeeepppp, but it wont lock the doors. First time it happened I just got back in the car, started the engine and turned it off again then got out and pressed lock on the remote and it worked fine. I figured maybe it had something to do with a window not being properly closed but I tested it by leaving a window half way open to see if it would lock and it worked with no problems .

 

Check to see if the trunk lid is closed.

 

Put your key in the ignition, wiggle it around a bit and remove - then retry the key fob. the gate over the key slot can stick, and it's switch being still open tells the system that your keys are still in the ignition - it won't lock with the fob and warns you about it.

 

So it sounds like the key slot may need a little lubrication eh? Thanks for the info.

 

Had the same problem recently. Used a bit of electronic component cleaner spray (from radio shack) to clean it. Works fine now.

 

What did you clean? The ignition key slot or the remote? I don't think my problem is the remote.

 

Sorry for the lack of clarity. The ignition key slot. The gate over the key hole that Quad mentions above sticks. I used electronic component spray cleaner to clean the gate, because I assumed that something like WD-40 or graphite lubricant spray might produce undesirable results.