Lexus IS250 Computer shutting down

[Ben T.]

Hi all - I have a Lexus IS250 2007 which has been a great car. Unfortunately now the computer shuts down when it's hot outside. It's totally fine during winter but as the days get hotter it's shutting down more often - sometimes when I press particular buttons, sometimes it just doesn't turn on.

Any advice? Lexus advised I'd just need to replace the whole system.

Assistance would be much appreciated.

Cheers,

Ben