Gs300 And Gs450H Navigation System Screen

erickelsall · June 15, 2012

Hello Everybody,

I have a GS300 SE-L 2006, and this is by far the best car I have ever owned. Quiet, comfy eats the miles and get treated well when at Lexus Manchester!!!

But here’s the problem. Last year I had an issue which was completely of my own doing, or should I say my daughters. She was messing around in the centre console and had a fizzy drink in her hand which she spilled down the front of the buttons on the AC just under the NAV touch screen. Needless to say this caused problems lol. To cut a long story short I lost function of all the buttons around my nav screen including AC/Heater for the rear window etc. I initially took the car to Lexus where I was told the unit was beyond repair and that a reconditioned unit would cost £1500+Vat (plus they keep your old one!).

I thought this was very heavy, and considering I could still use the Touch screen itself and adjust the temp with speech control via the steering wheel I decided against giving Lexus all my money!

I am an electronics engineer, so one year on and getting fed up with not being able to see through the rear window in the cold I thought I would see what the problem was and see if I could resolve myself. I checked all the fuses (damn this thing has more fuses than the space shuttle!) and all seemed OK. So now I decided to remove the entire NAV/Audio console from the car to take a look. I was very apprehensive about this, but trust me it is so easy to take out it’s untrue, I had it out in 5mins (found a great video on you tube)

Once it was out I realised that the Navigation system has an ECU behind it and this would be the culprit for sure, as the surround with the failed buttons was connected to it. But could I get hold of one these!!! No chance, Lexus/Toyota only sell the entire unit and units on fleabay come up very rarely and get snapped up quickly for silly money £400-800.

After weeks of hunting scrap yards I found one. Hooray!! It was like finding a Willy wonker's golden ticket. And the price you ask? £300+Vat. A good price considering the ones I had seen over the last year. So I awaited the unit like a child, everyday waiting by the window for my knight in his brown UPS van. And low and behold it came two days later :-) So I had all I needed to get this done. I took out my old unit imagining how good my car will be once I can use the buttons around my SAT NAV screen, and then it hit me like a ton of bricks. The donor unit from the scrap yard was from a GS450H (Hybrid model) and completely a different ECU for NAV and electronics so would not fit. AAAARRRRRRRRRRRRRRRRRRRRRRRR!!!!!!!

So anyone want to buy a GS450H NAV (2007) head unit for £250? It has a couple of scratches on the plastic protector over the touch screen but other than that it works well. I know this because my car will power this unit up, but two DIN connectors are different. The Lexus/Toyota part number is 86111-30570

ColinBarber · June 15, 2012

isn't the problem just with the buttons. Would have thought it would be possible to disassemble and clean/repair.

erickelsall · June 15, 2012

Hi there,

No its not that the buttons need cleaning/repairing. They are not sticky and dont light anymore (no power). The liquid ran on the circuit board and blew it at the ECU (where the NAV surround) is connected. I have opened the ECU and located the blown transistor on the board, but its too small to replace by me. I have tried specialist electronics companies, but no one will touch it.

Looks like my hunt for a new GS300 NAV ECU continues.........................................

ColinBarber · June 16, 2012

can you identify the transistor? If we can source the component I'm sure we can get it replaced.

PJ S · June 16, 2012

Check this thread out first - http://www.clublexus.com/forums/gs-third-generation/587356-my-conversion-from-gen4-to-gen5-nav-and-mp3-player.html

WoodcotePark · June 17, 2012

You may have been just looking on eBay UK. It's worth thinking about whether you want to use eBay worldwide - both to get the correct bit, and to sell your unwanted bit.

A few years ago I had a '99 GS300 with a broken CD mulitdisk. It was impossible to find a cheap replacement in the UK, but I found one in seconds in the US - at a very low price. OK, it cost some money to get it posted and to pay import duties, but it still came out MUCH cheaper.