Since weve changed the batteries in our remote for the keyless entry, our car has started playing up majorly.

We cant get into the car without setting the alarm off - and thats by using the actual key and turning the lock (its the only way we can get into the car at the moment - even with the new batteries fitted).

Also i can have started the engine and set off on my journey only to have 'KEY NOT DETECTED' flash up on the dash. Bit worrying when you know it will cut out if you drive off without the keys actually in the car.

Last friday i couldnt get the car started at all as it wouldnt register either sets of keys as being near the start button!

This morning only the drivers door would open (with the alarm going on its second round) so i shut the door and tried to lock it and unlock it to get the rear doors open for the kids. WHen i shut the door it locked automatically with my keys still inside. It was only by fluke that i'd brought hubbys keys to the car with me that i could get inside again (yep alarm went off again) and get my own keys back.

Anyways, to cut a long story short i found myself at a LEXUS dealer in hannover at lunchtime, only for them to find no problem with the car. TYPICAL. So i drive all the way home get out and try to lock the car - only to find that the car wont lock with the keyless system again.

Has anyone else had similar problems? Or is it really just genuine fluke that this is happening?

Take the car round the corner and try to lock it, sounds like interference.

hi yes i have this problem, it's going in to lex derby tomorrow this is a known fault i understand and is as has

been suggested to do with interference maybe by wi-fi router etc. there is a fix i think it involves dash out

for new receiver and new keys to alter the frequency.

while in the dealership a gent who must have overheard advised that vw had the same problem with the passat.

thanks for your replies, they are much appreciated.

The guy in the Lexus garage did say that it could be interference of some sort - but he followed on by saying i'd have to live near an airport to have such problems!

So you reckon i could need a change of keys or frequency thingymebob etc? Ive got the car going in for its first service on saturday so i might ask then about it then. DO you think we'd have to pay for it? Its not our fault we live where we live. Hubby is in the army so we get no choice in the matter. Typically though, there is another Lexus living literally around the corner from us. I'm so tempted to knock their door and ask if they have problems where they park. And if they dont then i shall be parking ours right beside it. lmao

had my car 10 months it's only started to happen in the last few days.

i never asked if it was covered under the warrenty just thought it would be because as being able to open and lock

your car is a basic security function for insurance. if the lex round the corner is on a different frequency then no problem

or it could be that a few yards is enough to take it out of range of the interference.

hope this helps

This is a well known problem with all manufacturers who use keyless entry.

Had a colleague with a Subaru who, every time he parked at the chippy near where we worked, couldn't get into his car with the fob and, once inside it wouldn't start. Had to push it about 30 yards down the road and then it would start. Eventually (DOH) he realised that behind the shops was a mobile phone mast and it was this that was interfering with the electronics of his car.

The advent of wi-fi has just compounded the problem of EMI.

Hi - I am a recent Lexus owner - secondhand 2001 IS200SE - I had a similar problem. I left the car for a week or so and the keys with some friends. When I collected the car the remote would not work and like you opened the drivers door manually with the key that started the car alarm off.
Put the key in the ignition and started the car & was ok.
I think once the key warmed up it had a little more life to lock the car remotley.
I changed the battery and all seems well now - I know you said you changed the battery but they are fiddley - maybe try reinstalling battey - check polarity possibly.
I have heard that you may only get a certain time to change the battery in the key fob (ie remove old one & replace with new one) so that code is not lost.
As others have said, I had a Micra out on hire and same thing happened in a petrol station - it would not start with keyless ignition - hire repair guys said push away from petrol pump which did the trick.

That is by design. If you open the car using the key in the lock then you will set the alarm off.

With most keyless systems or any remote for that matter radio masts or other interference can cause problems an jam your signal. To solve this problem and open the car or start it just hold the remote close to the start button to start or close to the door handle on the Lexus where I think the antenna is and it should work. the close range will cancel the interference signals if they are not too strong.

Good old brut force resolves issues with too much technology

It does worry me - the transmitter probably use standard radio waves, which is what most AV senders, WiFi etc use. I remember parking at a Merc garage, and my Audi's remote wouldn't unlock the doors, but the chap in am AMG CL 55 walked up and got in no probs "keyless" and drove off. Especially embarrassing when the salesman is pricing my car...he then told me that the 30ft mobile mast 10 yards away from my car could be causing the problem....which it was!!

update

well took the car in tuesday decided to wait as service advised it wasn't a long job ( took approx 1 hour )

and it's now working fine. and no charge.

Not had a problem with keyless until this weekend

My son has gone away on holiday so he has parked his car where I normally park.

Key system shut down completely being closer to the house

Decided my Wireless network was blocking key being only about 8ft from router.

Switched network off and all ok once I had reset key.

Parking on the road till he gets back !