Restart LS400 after new battery

[Clarke692]

Hi, just joined this forum having looked around various links and found this one to be really useful when trying to work through Lexus problems.  Working with my son on two 1995 LS400s (Mk2 - N plates) and have had to do a Battery swap out on both.  One starts fine but the other doesn't want to turn over (security light on with four-way indicators flashing).  The electrics work when I turn the key (seats/windows etc) so I know the Battery connection is fine but I've heard that you need to reset the car security system?  Nothing in the owners manual about how to do this so looking for some wise words to get the car back on the road.

Thanks in advance.

[Malc]

16 minutes ago, Clarke692 said:

Nothing in the owners manual about how to do this

I would say that with my Battery changes there's never been a need to reset anything apart from the steering position ......  and no radio code either on mine to worry over

I hope someone on here can advise you specifically ........

Malc

[ambermarine]

Make sure your key fob Battery is up to scratch.Turn everything off on the car and remove the Battery terminals refit them negative first ,then open the drivers door by hand ,close the door and leave the car for a minute then press the locking button on the key once wait then press the unlock button ,get in the car and turn the ignition key to the start position the car should start.

[Howplum]

When I got my 1996 project last year I had problems with the security system, especially as described by you. I had it disconnected in the end. Anyway, the supplement in my Owner's Manual explains the reset procedure, as attached.

[Malc]

Ah yes I remember now ........  should the keyfob Battery be anything other than 100% then no matter how brilliant your main car Battery, stuff will often not work properly

Malc

[messi]

Reset procedure:

Put the key into the ignition

Turn to the lights, don't start the car

Leave it like that for 6 mins

Then switch off, and then on and car should start  

[Clarke692]

Thanks for all your replies.  

 

Messi - Tried the key in the ignition in the on position without turning the engine on and leaving it for 6 mins but that didn't work.  So tried the 'holding key fob down for 10 secs' and then pressing again afterwards and it has worked so far.  Seems though that i now have to do this every time I lock the car which might drain the key fob on what is an already old fob...but at least I can get it driving! 

[Howplum]

Enjoy!

[Malc]

1 hour ago, Clarke692 said:

might drain the key fob on what is an already old fob

then change the keyfob Battery pronto !

Malc