Kendrick07

Hi, my sibling's 2006 IS250 gets the "External System Not Connected" message when trying to use her navigation. We took it to the dealer and they are asking $1700 for the part 8642153020A to fix it, and they are asking for the old one back. I've done a lot of searching, but nobody seems to have found a solution to it besides buying this part. Does anybody have an alternative solution or know what the cause is? The fact that they are asking for the old one back leads me to believe it can be repaired. She's the first owner and her car has always been completely stock. It just started happening recently. Thank you.

Gville350

iTrader: (10)

That P/N 8642153020A doesn't come up for me. Is it the Nav unit in the dash itself or the nav disk reader that they are attempting to replace? I would first try disconnecting the battery and reconnecting it. If that doesn't help, play with the cables that connect into the rear of the Nav disk reader. If that doesn't help, get an aftermarket in-dash unit for MUCH less than what Lexus is asking. Something this is popular :

KillaIS250

iTrader: (1)

Have you tried disconnecting the battery for a while and reconnecting to see if that fixes your issue?

Kendrick07

Hey guys, yeah I've tried disconnecting the battery for 30 minutes already with no success. Someone in another thread mentioned disconnecting the amp too which I also tried, but that didn't work either. That part number is for the disk reader. Try looking up the part number without the A at the end. The quote from the dealer had the A at the end. Anyone else have some insight? Thanks.

tex2670

I would ask them why they want the old part back. Many states have laws that require repair shops to give you the old part if you ask for it. The only reason i can think of is if there is something in that part that requires it to be disposed of in a particular manner (like when you see a disposal fee for tires or used oil or a battery after a repair).

IS-K

Wassup everyone,

Just want to share my 2c and provide some feedback in hopes to find a solution. So first off, I've had the same issue as OP with my '06 IS250 a while back.

From my experience and attempts in solving my NAVI issues, this is what I've tried and experienced on a high level:

- Navi was updated with a self-made 2010 Maps v9.1?? (cannot remember the exact version number)
- This update removed the "I Agree" @ startup
- Worked flawlessly for 1+ year (conclusion: update disk is not the issue here)
- Main vehicle battery started acting up (saw lots of build up on the negative terminal)
- While driving one day, navi all of a sudden stopped working (while driving)
- Intermittently worked and saw "External System Not Connected" message
- Attempted all fix suggestions found on forums/YT/etc (ie. disconnect battery, finger tap to eject disk, hold info button and switch headlights 4x for secret service menu,..) and was successful at ejecting dvd disk
- Placed original disk back into navi when successfully ejected update disk
- Started rebooting and seemed to work for a little while w/original disk
- ***STUPID MOVE*** While wanting to keep features/maps of updated disk, placed update disk back into navi and successfully worked for one drive, upon next car start, navi failed again, black screen with "External System Not Connected" error message
- Removed navi from dash and disconnected all cables in the back (in case it was a loose cable problem), did not help
- Removed TV fuse and Radio fuse, no success
- Eventually replaced battery (w/ update disk in navi)
- Now cannot eject update disk with all previously working methods
- Now still stuck on black screen with "External System Not Connected" error message

A few thoughts
- Process of elimination: Eliminated other possible issues such as circuitry/pen correct issue or touch screen calibration. Narrowed it down to navi disk (unless others have input/thoughts to share).

- Disconnecting battery: Early attempts this method did allow me to eject the DVD from my navi, seemed to reboot navi system but must be kept disconnected for an extended period of time (5mins +, I did more like 15mins +). Now with my new battery and update disk in, disconnecting battery does not help at all. Actually nothing ejects the navi disk for me now, while finger tap method did work once upon a time...

- Amp Cable: I never touched the amp cable, and since OP has tried with no success, I have not try this method.

In the process I did scuffed up my dash (which is sad) because I did not use the right tools for removing the vent. Let that be a reminder if you're attempting to remove the vent where the navi sits under, use the proper caution and tools. I was real careful and used tape and everything and still turned out scuffed. The material of our dash is very fragile. ***YOU'VE BEEN WARNED***. Don't make this same mistake as I...

Sorry for the long post, hope this info was helpful and I tried to be as detailed as possible and back track what I've done.

Conclusion though, my navi is still not working. My new strategy/direction is to first eject the update disk, then try with original and if all goes well, will try a NEW update disk to remove "I Agree" because this feature is sooo nice to have!


Cheers,
Ken

Kendrick07

Ken, Thanks for the informative post. Yes, we are still stuck on this as well. Seems like it only happens to 06 IS250s. Sorry you didn't ever get it resolved after all the trouble. We might just have to bite the bullet and buy it from the dealer. Really appreciate the replies.

rramire7

Hi Kendrick07, did you ever figure out a solution? I am new to the forum here, and I recently have experienced the same issueyou described. I pushed the info button and turned the lights on and off and that made it work again for about 10 seconds. Now it works sporatically for short amounts of time. It seems almost linked to bumps in the road. Other times the screen will just have colored vertical lines across the whole screen and then go blank. When I push the maps button, the error message pops up in the top right hand corner which reads "The External System is not Connected." I have also seen a screen that shows a disc and a message that reads "System loading do not turn off power"...Any help would be appreciated.

Thanks!

Rob

Kendrick07

Rob, no we haven't found a solution. The navigation actually started to work one day, but then went out again the day after. I'm wondering if it's something as simple as a loose connection. I just haven't had time to take the unit out for a look. Seems like the most common diagnosis for this is a bad printed circuit board in the nav unit behind the screen and only way to fix it is to replace it. My guess is yours is a 2006 model as well? I will post something here if I find any alternative solution to replacing the whole board which costs almost a couple grand. Good luck to us all.

IS-K

Kendrick any new solutions or attempts at solving the navi issues? I've done some more research and found other members with navi issues where the navi ECU is the culprit. I'm wondering now how to determine whether it's a navi ECU issue. What are some symptoms?

My navi is still out but the Lexus logo still boots when I start the car and all non-navi functions still work (including reverse camera). I'm leaning towards manually removing the navi disc as a next attempt. Please let me know if you have any new updates.

Cheers,
Ken

AZ06IS350

How do you manually remove the navi disk? I'm having the same issues and have tried to get the disc out with no success.

IS-K

AZ06IS350 you have to take the navi unit out completely and dissemble the dvd drive to get to the disc. The circuit pen DIY has good instructions on taking the unit out. This is definitely my last resort/option as its the most time consuming option. Wanted to revisit this thread to see if Kendrick had any updates or whether other members have chimed in with solutions.

Right now the finger tap trick after disconnecting the battery is not working for me anymore to eject the disc (you might want to try that first) and I'm trying to determine whether my issue is related to a bad navi ECU or bad disc by trying first to take the bad disc out and put the original one back in. There have been many ppl with navi issues so narrowing down my individual issue has been a challenge as info I've found seem to match my problem but not exactly the same.

Regarding my last post, I'm not sure if my problem is related to a bad navi ECU since the Lexus logo still boots, the touch screen still works with a/c, audio, phone, bluetooth, etc.

AZ06IS350 does your screen display the Lexus logo when you first start the car or is it completely a black screen?

AZ06IS350

When I first start the car, the Lexus logo appears then the screen goes black. I've been told that the Lexus logo has nothing to do with the nav ecu and that it's the ecu that fried on me. I have a friend who works in the parts dept. at the Lexus dealership in my area and he told me that after consulting with techs, one of which I know personally as well.

IS-K

AZ06IS350 how did you determine conclusively your problem is the navi ECU? Any particular symptoms?

My navi issues really first started when my car battery was acting up (time to replace). Not sure if that was something you experienced as well.

AZ06IS350

The only way to know with 100% certainty that it is the navi ECU is to swap it out with a functioning one and see if the problem goes away. I am basing my conclusion on the fact that it is not a wiring issue nor a fuse issue as I have eliminated those as possibilities, and that only my navigation is not working (the touch screen works fine and my climate control, audio, info, and display buttons also work just fine). I have not had any other symptoms, like a bad battery, as you said you had, IS-K. Aside from the navi ecu, the only other thing that would make sense is a bad disc which I currently am unable to retrieve from the unit. My friend at the dealership said that if it was the disc that went bad, I should still get a generic map appear on the screen and that I wouldn't be getting the message saying the "External system is not connected". I really wish I could get that disc out some easy way, but have had no luck up to this point. I would like to get more info about this "finger tap method" you mentioned.