this has been driving me mad for a few days now and I cant understand it. Basically the key fobs for both the lexus and my van won't work when parked at the house, both work away from the house but have to use the key when we get home to look them. What can cause this lol seems so stupid lol

The Scorpion Alarm on the Z does this, it's weird, thankfully I don't have any problems at home, but the last time it happened I was on the top floor of a multi-story car park in Hammersmith, at 7pm, wanting to get in the car and drive back to Doncaster, needless to say the hour and half it took me to open the car was NOT fun! I've come to the conclusion though, that the alarm is getting problems with electro-static/magnetic fields, because every time I park it too close to something, say a lamp post etc. it gets this problem.

A possibility below:

 

http://www.formby.gb.com/southport/news_photo/Mystery_Key_Fob_SOLVED_for_New_Cut_Lane_resident-50777392.htm

 

Look for anything, transmitters, etc that might interfere

We do have a wireless alarm system for the house but it's never been used for years lol. They have had a problem with the O2 telephone mast which I think has now been fixed and the wife says the lexus locked ok tonight

Any electrical pilons near by ?

Stopped working again. There is nothing new that I can think of we have been here for just over 4 years this is the first its happened you can get it to work if you put it right up against the windscreen

My Dad's car will only lock on the drive if you reverse it up - very weird interference, never got to the bottom of it! Someone, on here I think, mentioned putting the fob to your chin to boost the signal... sounds like a joke, but I now do it instinctively when I come out of the supermarket - I have a tendency to forget where I parked, it boosts the signal and I look for the lights flashing!! Worth a go!

Wireless video senders are a big cause of this, but in theory any wireless transmitter can interfere with another if the frequencies are close enough.

My Dad's car will only lock on the drive if you reverse it up - very weird interference, never got to the bottom of it! Someone, on here I think, mentioned putting the fob to your chin to boost the signal... sounds like a joke, but I now do it instinctively when I come out of the supermarket - I have a tendency to forget where I parked, it boosts the signal and I look for the lights flashing!! Worth a go!

 

I tend to put it to my temple, direct route to the eye ;)