02 LX470 - Check connection of air conditioner + Touch Screen Unresponsive (2 Viewers)

[quikcslvrsrfr]

Hello,

My 2002 LX470 has this intermittent issue where the following things happen -
- touch screen doesn't load, black screen
- when I access climate settings, I see a message - Check connection of air conditioner
- Audio is switched off
- none of the touch screen related controls function properly
- when accessing the system is slow to respond (lots of lag before I hear a button beep)
- the AC works, it blows cold air, I'm presuming just using the previous settings, but the touch screen and physical buttons are all off so can't really do anything

Besides this, I haven't noticed anything else not working. I've checked the fuses, and they seem to be fine. I've checked for water leakage, and the car seems to be dry throughout. Also the issue seems to come up after somewhat extreme weather conditions - either a lot of rain / humidity or after a lot of heat.

I also have a BT45-TOY installed for bluetooth.

I've browsed several forums for this issue, and there seem to be quite a number of posts related to it, but haven't come across a single thread which clearly mentions a fix. I'm referencing the posts here in case someone else tries to do a similar search.

Nav Unit "check connection to Air Conditioner"

so not to long back i upgraded my sound system, amp, speakers, and sub, they bypassed the OEM amp in order to keep my Nav all happy. So today it is raining like a bitch outside and i see water seeping in through my sunroof. I figured my drains were plugged and i'll clean them out. I also...

forum.ih8mud.com

- mentioned water leak as a potential root cause

Changed nav unit climate control still doesnt work - ClubLexus - Lexus Forum Discussion

LS - 3rd Gen (2001-2006) - Changed nav unit climate control still doesnt work - Previous nav unit had gone completely dark. This newly installed one just shows this: https://i.postimg.cc/g04b14q9/9-FDB1-AC4-CE75-41-F0-B795-5377-B5-AC69-DB.jpg (https://postimg.cc/p99SFf6k) Fuses were tested. Any...

www.clublexus.com

- another thread on similar issue which I don't fully understand

Dreaded MFD Issues - Reputable shop to diagnose it?

Dreaded Multi Function Display (Nav) Issues - how to diagnose? I've got the dreaded Multi-function Display issues where the screen is blacked out and displays "External System is not connected" when clicking map or dest and "check the connection to the air conditioner" when i click climate...

forum.ih8mud.com

- external system not connected / check connection of air conditioner, 2005+ model, potentially an issue with an aftermarket device (VAISTech) install.

I will be opening up the nav unit and check to see if the BT45 is causing issues, but I just wanted to post this in case a kind member takes pity on my noobness, and helps me out with a known fix. I haven't been able to deduce anything substantial from my searches.

Thanks, and appreciate your help with this!

 

[excessive]

I had a simliar problem on my 2004 Lexus LS430 (very similar integrated NAV to the LX470) and the fix was getting a new (used) LCD screen from ebay

 

[Red Beard]

Hello,

My 2002 LX470 has this intermittent issue where the following things happen -
- touch screen doesn't load, black screen
- when I access climate settings, I see a message - Check connection of air conditioner
- Audio is switched off
- none of the touch screen related controls function properly
- when accessing the system is slow to respond (lots of lag before I hear a button beep)
- the AC works, it blows cold air, I'm presuming just using the previous settings, but the touch screen and physical buttons are all off so can't really do anything

Besides this, I haven't noticed anything else not working. I've checked the fuses, and they seem to be fine. I've checked for water leakage, and the car seems to be dry throughout. Also the issue seems to come up after somewhat extreme weather conditions - either a lot of rain / humidity or after a lot of heat.

I also have a BT45-TOY installed for bluetooth.

I've browsed several forums for this issue, and there seem to be quite a number of posts related to it, but haven't come across a single thread which clearly mentions a fix. I'm referencing the posts here in case someone else tries to do a similar search.

Nav Unit "check connection to Air Conditioner"

so not to long back i upgraded my sound system, amp, speakers, and sub, they bypassed the OEM amp in order to keep my Nav all happy. So today it is raining like a bitch outside and i see water seeping in through my sunroof. I figured my drains were plugged and i'll clean them out. I also...

forum.ih8mud.com

- mentioned water leak as a potential root cause

Changed nav unit climate control still doesnt work - ClubLexus - Lexus Forum Discussion

LS - 3rd Gen (2001-2006) - Changed nav unit climate control still doesnt work - Previous nav unit had gone completely dark. This newly installed one just shows this: https://i.postimg.cc/g04b14q9/9-FDB1-AC4-CE75-41-F0-B795-5377-B5-AC69-DB.jpg (https://postimg.cc/p99SFf6k) Fuses were tested. Any...

www.clublexus.com

- another thread on similar issue which I don't fully understand

Dreaded MFD Issues - Reputable shop to diagnose it?

Dreaded Multi Function Display (Nav) Issues - how to diagnose? I've got the dreaded Multi-function Display issues where the screen is blacked out and displays "External System is not connected" when clicking map or dest and "check the connection to the air conditioner" when i click climate...

forum.ih8mud.com

- external system not connected / check connection of air conditioner, 2005+ model, potentially an issue with an aftermarket device (VAISTech) install.

I will be opening up the nav unit and check to see if the BT45 is causing issues, but I just wanted to post this in case a kind member takes pity on my noobness, and helps me out with a known fix. I haven't been able to deduce anything substantial from my searches.

Thanks, and appreciate your help with this!

My 2006 is going through the same issues. You can see my thread here: Are 06-07 Cruisers affected by the Pin 60 problem? - https://forum.ih8mud.com/threads/are-06-07-cruisers-affected-by-the-pin-60-problem.1290920/

Have you tried wiggling the wires behind the head unit? Especially the top? I think another member mentioned that might indicate a pin 60 problem.

I also had a BT TOY, but moved to a Grom VLine. I wonder if these aftermarket systems put a strain on the tech.

On my thread, you’ll notice @Couvi mentions replacing the Network Gateway. You may want to start there.

I have an AC amp for you (#88650-60850) if you want to try replacing that, you can buy it for what I bought it for, I think it was $24, you just gotta pay shipping. I never used it, I bought the wrong one. Seller said it worked fine.

 

[quikcslvrsrfr]

@excessive , @Red Beard - Thank you very much for the replies!

@Red Beard
Thank you for all the information. I think this has been the most informative / clear post I've seen so far on the issue.
PartSouq was a great recommendation, I have bookmarked this.

So based on what I've read the following things could be a potential issue -

Fuses
Basic check

Pin 60 Issue or Multi-Function Display
Bad solders on the circuit board, and there seem to be service alerts about this.
Based on what @excessive recommends, could be simply a broken MFD unit or a unit with the Pin 60 issue.

DIY: 2004 Multi Function Display (MFD) PIN 60 Repair

****Please Do Not Attempt This If You're Not Willing To Ruin Your MFD**** (But it's already broken anyway, right?) Seriously though I take no responsibility for you messing up your junk. After several months of intermittent failure of the "dreaded MFD" issue I decided it was time to do...

forum.ih8mud.com

AC Amp or Gateway ECU

Are 06-07 Cruisers affected by the Pin 60 problem?

I've been doing some reading and a lot of my symptoms point to a Pin 60 problem. It's consistent with the prius documents as well. I can repair or try to replace with this from Aliexpress. My question is, are 2006 Cruisers affected by the same Pin 60 problem? I thought Toyota fixed the Pin 60...

forum.ih8mud.com

I don't believe the Navigation ECU is the problem because the navigation was working fine for me. Also I don't see the message such as 'External system not connected'.
Based on this I feel like my issue is probably in the Multi-Function display, the AC Amp, or the Gateway ECU.

I'll try and start with the MFD because I feel that's where the issue is. Yesterday during some more debugging, I realized that even though the display says 'Audio Off' the FM, AM still work. The Disc doesn't, but that maybe because of the BT45, which also makes me wonder if it's the aftermarket part that has been causing these issues.

@Red Beard - Look forward to your explorations, and see if the Network Gateway resolves the issue. And maybe I'll reach out to you for that AC amp if it comes to that. Thanks for the offer. Best of luck!

 

[Red Beard]

@quikcslvrsrfr Yeah this is like a tracking down a short, it can drive someone crazy.

I have the same condition with the AM and FM still working even though it says Audio Off. But I do have that external system error message, so maybe you're right about the nav.

Have you tried wiggling the connectors on the MFD?

I'll update my post when I get the parts in next week and I'll tag you if I get anything good.

 

[quikcslvrsrfr]

I agree, it's been annoying.
Another thought is whether the Nav issue is a symptom of the root cause somewhere in the MFD. Not sure...
I'm hoping today I get some time to open it all up and see if it fixes something.

 

[quikcslvrsrfr]

@Red Beard - Jiggling the works worked out!! I just opened up the console, and tried readjusting the wires - and suddenly everything started working again.
So, makes me think that there is probably a loose connection somewhere in the MFD. For now, I'll see how long this takes me, and will do the Pin 60 project on a lazier weekend.

Hope things work out for you as well. Good luck!

 

[Red Beard]

Love that. So wiggling could be a good indicator of the Pin 60 problem as mentioned by another member here.

 

[jsloden]

I had this problem when I tried installing a bt45 in my truck. It did the same thing. It was fine when I removed it. After I sent it back I read somewhere that if you unhook the battery before installing the unit then hook it back up afterwards this will solve the issue. You might want to unhook the battery for several minutes and see if that helps.

 

[Red Beard]

@quikcslvrsrfr New Nav ECU solved it for me. I just updated my thread with some more info on it.

 

[quikcslvrsrfr]

@quikcslvrsrfr New Nav ECU solved it for me. I just updated my thread with some more info on it.

@Red Beard - Awesome! Glad you got it working. Onto the next project -

 

[quikcslvrsrfr]

I had this problem when I tried installing a bt45 in my truck. It did the same thing. It was fine when I removed it. After I sent it back I read somewhere that if you unhook the battery before installing the unit then hook it back up afterwards this will solve the issue. You might want to unhook the battery for several minutes and see if that helps.

@jsloden - Interesting! Can't remember if I disconnected the battery when I installed mine. I'm thinking to give it another go around, and install the mic also. Didn't do that last time. Appreciate the tip!

Btw, what's your set up now, after BT45? I just like the relative 'stockness' of the install, but hate the 'CONNECTED' announcement if I leave it on high volume.

 

[jsloden]

@jsloden - Interesting! Can't remember if I disconnected the battery when I installed mine. I'm thinking to give it another go around, and install the mic also. Didn't do that last time. Appreciate the tip!

Btw, what's your set up now, after BT45? I just like the relative 'stockness' of the install, but hate the 'CONNECTED' announcement if I leave it on high volume.

Right now back to stock. Thinking about ordering another one.