I realize this could be as simple as the lithium battery needing to be replaced, but I am having problems locking my 05 Boxster by the remote every once in a while.
The light on the remote does not light when this happens, so most likelya bad remote battery?
I always visually check to see that the lights flash twice to make sure it is locked. I know most of you prefer the "no horn" comfirmation but do others worry that the remote may have failed and the car is not actually locked without a horn confirmation? THis has happened to me twice where the car was not actually locked when I thought it was.
Will replace the lithium battery and see if this is simply the problem.
Similar thing started happening to me on my 05 Boxster S after I took the car in for warranty service. The FOB would not always lock/unlock the car, the problem went away the following week only to return a week later. Unlike your issue though, my FOB now no longer locks or unlocks my car at all, I've been using the key, which is not that big of a deal since the Box is not driven that much but if I just unlock the car and don't put the key in the ignition within a minute, the alarm goes off.
I've dropped my key several times over the years, so I've chalked up the glitchy operation to that. These days I just make sure I hear the "ca chunk" of the doors locking before I walk away. For me, the blinking lights are not reassuring. The ch chunk is.
Maybe I need batteries. Never thought of that. I'll have to replace it.
These batteries seems to last about 3 years (CR-2032) in my experience.
3 things can go wrong:
-half dead battery = cheap fix
-sick key = $300?
-sick car remote pick up sensor = $$$
I say change the battery first. You might as well try the second key(with new battery) to make sure the remote pick up sensor in the car is working.
It is also possible that you're getting EM interference. When we park one of the Porsches in the garage bay near our home electrical panel the remotes don't work. One bay over, no problem. It took me a while to diagnose that one.