My key fob will open and lock the car doors properly but wont let me open the trunk ....... I have to insert the fob into the ignition to start the car .... I cant start the car when the key fob is in my pocket ?

Any ideas why this happens after 17 years of working flawlessly ?

 

Are you using your valet key per chance? If not maybe try a new battery in the fob.

 

nope. Not using a key, using a plastic fob.g
First thing I did was to replace the battery and it didnt make any difference.
I did just notice that the red light to the left of the steering wheel does not flash when I enter the car, which makes me think for some reason the car does not detect the key. Is there some way to reset this ? Disconnect the battery maybe ?

Thanks

 

ALL FIXED !

The key switch, beside the low tire reset button, was pressed by mistake when I was resetting the low tire warning light ......... still learning stuff about this car !

 

I knew that button you're referring to is to shut off the smartkey access, (to save the car's battery/long term storage/etc), but weird that your fob continued to lock/unlock the doors, with Smartkey off.

 

Pretty sure he meant that pressing the buttons on the fob locked/unlocked the car.
As for the Trunk, if it has a Trunk button on the fob, but it doesn't work to release the trunk (you still have to lift it manually) then the button in the fob must have failed.
The Valet fob does not have a Trunk button at all so pressing that blank area has no effect.

 

Oops. I meant to say the smart key would not start the car unless it was placed in the ignition.

 

LS430 should have come with 2 key fobs which look identical. 1 is drivers and fob 1 is valet fob. The functions you have described are the same as the valet key functions. Have you switched keys by mistake perhaps? As the other post says, you can confirm if you've switched keys because there is no picture of a trunk on the valet key.
If not, the fob you are using may be faulty/needs to be reprogrammed. There are plenty of threads about DIY reprogramming key fobs and cheap key replacement options
Also, key remotes can sometimes get scrambled by other radio frequencies i.e. cell phones or other key fobs near to it.
EG my LS key doesnt work when in same pocket as my phone/other keys