I have a problem i have a 98 gs400 with stock navi but some controls dont work the treble bass Basically the audio control buttons dont work. also the navi screen looks messed up look like it been scrambled a little on the top of the screen so it doesnt look real nice.
1So i was wanting to see if there is a fix for this.
2if not i would like to see if i could buy a new deck or sumthin
3 last of all or could i replace if with an after market unit

thanks for all your help

 

i would do the navi system check...

CEO

 

how you do that