SpeedFour

So, last week the Navi crapped out, screen blank nada info. BUT the radio and climate screens were fine and those functions worked. I figured no big loss as I use the phone as a GPS.

Yesterday after a third start-up the radio came on and then went out. The screen froze and then went dark, eventually reverting to a picture of the speaker with the text 'audio off', but it would not turn on for anything. Alos, the AC screen reads "Connect Air Conditioner" lol. The rear view camera also no longer appears. So I am without climate control and audio (I miss the days of not having all my eggs in one unit )

Does this mean that the module under the passenger seat needs to be replaced (visually inspection and wiggle test ensures all connections are still firmly seated), or does it mean the screen unit needs to be replaced (as I'm assuming this is an unfixable issue)? If so, where is a decent place to source these parts (sewell is out of business right?)?

Or is there a troubleshooting action I can take?

Many thanks in advance!

SpeedFour

So the problem got weird, upon start up I had about thirty seconds to set the climate control or listen to the radio - the screen worked and the touch controls operated during this time (the map never came back on and the rear view camera would operate intermittently). Checked all the fuses and everything seemed fine.

Figured it had to have been the multiplex module under the seat (talk about a potential pricey self diagnosis). So I lucked into finding one from a crashed California GX on ebay for $90. I figured this was a steal as I couldn't find any others for sale and I wasn't prepared to ask the dealer for a price on a new OEM

Installed the new/used part and viola everything functions again as it should. So, just an FYI for anyone that finds themselves in a similar predicament .

Culprit:

shoehorny

Thanks for that info! I have a similar issue with my audio from the radio being out. I am fearing it will also be the amp, but this is the most f#@%ed up car I ever did work on! It seems if you even sneeze a dashboard light will come on. I was initially faced with no navigation system, no radio, no climate control and the VAS, TRAC and skidding car lights on the dashboard. Couldn't figure out how to get rid of the lights. Decided to check the fuses and found out the two radio fuses were blown under the hood fuse box. That distinguished the lights, and got the climate control and navigation system going but the radio would play no sound. I am guessing that whatever made those two fuses blow must have also fried that amp. I posted a question on this forum but nobody replied yet. Was the amp difficult to change? It seems the carpet under the passenger seat is glued down on top of it.

SpeedFour

It's not really an amp, but a multiplex control module for the voice, nav, gps, radio. All of these things failed to function for me and replacing it fixed the issues. The unit removal was pretty straight forward, two bolts up front and one at the back (the bracket goes under the carpet, but there was a slice large enough to pull away to get to the bolt). Unplug the connections and install the new one. Just the radio being out may be the head unit?

Also, all those warning lights being on is the GX's way of telling you the check engine light is on

shoehorny

All of those applications work for me (even the voice on the nav). The radio functions as normal, except no sound. It pulls in stations, tunes, etc. Also, no sound from CD player. Thanks for the instructions on pulling it out. I might just do that and re-install. I read that others said a diode was the problem.

Regarding those warning lights, what a PITA! That is way over-engineered and I would have paid to NOT have that information. But, I fixed all of them! Except for the flat tire indicator...heaven knows what's up with that one. All 5 tires, including the spare, are inflated to the proper specifications (32 psi). I probably need to change the cabin air filter or something to get it to turn off. Daffy system. Me no like.

Thanks!

MrJason

Just pull the passenger lower dash to reveal the TPMS module... cut the blue wire with white stripe, and ground the side coming from the harness.... the TPMS will never light up again. That was my fix.

SpeedFour

That is diabolically genius. I'll have to do that, no way I'm paying for new sensors, I actually check my tire pressure the old fashioned way

MrJason

Ive done it to both my 2005 GX470 and the 2005 4RUNNER limited. I check my pressures religiously anyway.. but that’s for gas mileage purposes.
If you have a GX470 and can’t tell when the pressure in one tire is just 10lbs low(much less, flat) then you shouldn’t be driving. Lol

tpms is a good thing for low pros or run flats though.