AlRose

I have a LS430 year 2003. When bought the s/n screen said Insert Disc. I checked the computer and found a Series 1 disc already installed.
I then swapped the computer from my previous car and this seemed to solve the problem for a while. However it often fails to follow my route.
and the location sign can be anywhere often hundreds of miles away from my position.

I can laboriously reset my home destination but after a few days it wanders off on its own. Another observation is that the Clock runs very slightly fast, I understand this also works from GPR.

Can anybody throw some light on this ? Lexus main dealer wants enough money which would enable me to buy several Garmins (probably more useful than the installed 2003 stuff) but it would be nice to get it working properly

Suggestions would be very much appreciated. Thank you.