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Hey guys I just bought my first Lexus I got a 99 ls400 so I have the gps system and it has a white screen nothing else……and the sun roof is not working any ideas…I’m gonna check fuses in the morning
Sounds like a common issue for GPS systems in Lexus vehicles of that era, here is a thread about it. You can try repairing the board as it is described in the thread, though an easier option would be to replace the unit with either the post-facelift model, where that issue got resolved, or a regular radio, which is a plug and play option, no alterations are required.
The white navi screen problem is mostly caused by the failed power supply unit indicated by the red arrow. LCDs become all white when drive signals are not coming from drivers.
At first, I'd try checking electrolytic capacitors on the board since drivers are getting the power from the board. Those capacitors usually fail when aged since those are infamous QAS capacitors as you can see the ID mark PL(M) . Similar problems are widely happening among ECUs. Simply replacing all those capacitors will fix the problem in most of cases.
In case of a 98-00, those capacitors used on the navi's power supply board fail before ECU capacitors fail, I must add. So those 98-00 navi model owners should pay more attentions on the navi compared with the ECU.
The white navi screen problem is mostly caused by the failed power supply unit indicated by the red arrow. LCDs become all white when drive signals are not coming from drivers.
At first, I'd try checking electrolytic capacitors on the board since drivers are getting the power from the board. Those capacitors usually fail when aged since those are infamous QAS capacitors as you can see the ID mark PL(M) . Similar problems are widely happening among ECUs. Simply replacing all those capacitors will fix the problem in most of cases.
In case of a 98-00, those capacitors used on the navi's power supply board fail before ECU capacitors fail, I must add. So those 98-00 navi model owners should pay more attentions on the navi compared with the ECU.
I have a 98ls with nav system and failing screen and already had the trunk disassembled to replace the o-rings in the air suspension valve and was thrilled to read this the other day, hoping to head off another problem without further disassembly. Unfortunately this image does not show the power supply for the nav computer in the trunk, but evidently for the head unit where the screen is located. BTW, the capacitors in the nav computer in the trunk are also the PL (M) capacitors. Might be wise to replace those before they leak and cause a mess.
I have a 98ls with nav system and failing screen and already had the trunk disassembled to replace the o-rings in the air suspension valve and was thrilled to read this the other day, hoping to head off another problem without further disassembly. Unfortunately this image does not show the power supply for the nav computer in the trunk, but evidently for the head unit where the screen is located. BTW, the capacitors in the nav computer in the trunk are also the PL (M) capacitors. Might be wise to replace those before they leak and cause a mess.
Has anyone done this fix?
Last edited by Sin1UZFE; Jun 18, 2023 at 03:32 PM.
GPS radio not working
