Dreaded MFD Issues - Reputable shop to diagnose it? (1 Viewer)

[agaisin]

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 control button.

Dealer says they pulled all the fuses and verified they were ok, and that all the connections in the back of the MFD are good, and said the Nav ECU was not responding and had to be replaced. They said dvd wouldn't eject and have to replace the dvd nav b/f they can diagnose any further. That's 2k and still may not be the end of it (if they replace the whole MFD that's at least another 4k on top).

It seems like a known issue that many out there with lx's, lc's, prius and many other toyotas/lexuses have experienced. In fact, there's a TSB on the topic (EL002-05.pdf).

Most dealers seem to want to replace everything rather than diagnosing the root of the problem and fixing that. Refurb units that used to be available are no longer available.

Then there are other people that have reset their nav ecus, or even soldered the connections together that lead to the MFD failure, and there are shops online that supposedly can fix the problem (if you know that's the cause). In my case, my car is an lx470 '05 with 76k miles and supposedly the MFD problem was fixed for '05 and on. I really am looking for knowledge automotive electronics experts to really diagnose the root of the problem and potentially fix the part rather than to guess at what else they can replace to make everything work.

I live in Northern Virginia and was wondering if anyone out there has recommendations for online or local shops?

Thanks in advance!
Art

 

[02 Beast]

That sucks, good luck!! I guess I will be w/out AC and heat if & when mine goes out. 4K... -that's what windows and sweatshirts are for.

 

[mtnracer]

There are several threads on mud about this. I remember a few people sending their ECU (or whatever the part is called) out for repair. That seems to run a few hundred $.

Anyone remember the name of the repair shop?

 

[agaisin]

How to diagnose and troubleshoot myself?

My trusted independant technician can't take a look at the car until Monday. Of course I can't help but try to figure it out on my own in the meantime.

I tried by using a code reader and no codes were showing up.

Next, I tried using the (little known?) Service Check Mode (on mine it's hold down info button + switch headlights on and off 3 times). This took me to the diagnostic mode where I could see more info. I was able to see that my battery was producing >13 Volts.

Also, when going to the service check mode it shows that EMV is OK, and all other devices showed up as NCON (not connected).

When I went to Lan Monitor mode, it said CHK and when i tap on that icon it shows me a bunch of DTC codes - all were 01-D5 except for one that was 01-D8.

01-D5 means "Absence of Registration Unit" and trouble area can be any of the following:
1. Power source circuit of the
component shown by the subcode
2. AVC-LAN circuit between the
radio and navigation assembly
and the component shown by the
sub-code
3. Component shown by the subcode


01-D8 means "No Response for Connection
Check" and trouble areas can be any of following:
1. Power source circuit of the
component shown by the subcode
2. AVC-LAN circuit between the
radio and navigation assembly
and the component shown by the
sub-code​

3. Component shown by the subcode

Also, the FSM gives a hint that "when +B short or GND short is detected in AVC-LAN circuit, communication stops, and audio system does not function normally."

Can anyone explain a few things to me:
1) does all the power to the devices go through one central device or one place - that's the place I want to confirm the power is getting.
2) what is +B and where is the ground and how would I be able to tell if a short occurred on either one?
3) which fuses would I be checking?
4) Also, to a beginner like myself it seems obvious that there's one central point of failure here causing all the devices not to be connected. The Nav DVD isn't ejecting either (yes I know to slide the lock and push). is it possible that there's one connection for power that's loose or disconnected and where would that be? Is it possible that a single fuse blew and which would that be (ACC?). Is it possible that a single device is shot like the nav computer and everything else shows up as not connected?

I'm a beginner with cars but love to learn and wondering if anyone can provide some pointers.

Thanks!​

 

[parnoren]

Where did you find the explanation of these codes? FSM?

 

[block]

When mine did the same thing last year the Lexus dealer said to send it here:

Mr. Whizard Technical Services - Instrument Cluster Repair, Speedometer Repair, Odometer Repair and Digital Dash Repair

Turnaround was less than a week, and it was only a few hundred bucks. Everything has worked fine since the repair ~18 months ago.
I highly recommend them.

Good luck

Block

 

[agaisin]

block - thanks for the reference. If I can get to the bottom of which piece needs to be replaced, I'll talk to them to see if it can be fixed b/f resorting to replacement.

The real question I have is which part of the system (if any) is failing? According to the dealer, they had to start by replacing the nav ecu (they quoted me 1800) and then who knows what they'd have me replace afterwards. At the dealership, I don't know if it's lack of knowledge, lack of analytical skills, laziness, customers that don't question/understand, or that they often deal with customers that have warranties but it's just too easy for their diagnoses to be "you need to replace" instead of fixing the real problem.

According to the independent tech I spoke with, he said it's highly unlikely that all the devices failed at the same time - more likely that there's something like a wiring harness or power supply or one of the connections in the back that looks secure but is really loose, etc.

So before tearing out the nav ecu and mfd etc, I would like to truly diagnose the part of the system that's failing.

 

[agaisin]

Where did you find the explanation of these codes? FSM?

I purchased one of the FSM's online on the cheap. Something tells me the one I bought has legit content but is not the complete OEM package b/c for example the BE section (Body Electrical) talks about how to get into the service check mode for the non-nav model, but for nav model it points me to a DI section I don't have.

The BE section included some of the info for the codes (the 01-D8) but for some reason it didn't list the 01-D5 - when i did the search online for something like "lan monitor 01-D5" I found the info I was looking for.

If you want more info but don't want to shell out for the FSM, you can also find all the FSM info PLUS latest info and training and TSB etc on the Toyota TIS site: techinfo.toyota.com. They charge for access but the 2 days is just 15 bucks.
Here's a list of the info they contain:
Library
Service Bulletins
Repair Manuals
Wiring Diagrams
New Car Features
Campaign Publications **
Accessory and Guides **
Collision Repair Manual
Owners Manuals
Scheduled Maintenance Guides **
Technical Training
Scan Tool / Reprogramming
Techstream Diagnostic Software
ECU Calibrations
Security
Key Codes
Immobilizer / Smart Key Reset

 

[Sandroad]

Go to know you're trying to get to the component failure. I suggest you either buy or take a look on-line (techtoyota) in the electrical diagrams book. With patience, you can trace all the wires, connectors, and components in the L.C. On your question about a reference to shorting +B, that's probably just refers to a black wire? One clue about the problem is the some owners have been able to get theirs repaired by sending off the display unit. That would indicate the failure is in it, and not elsewhere in the system. The electrical wiring diagram book for your year might help.

 

[parnoren]

When mine did the same thing last year the Lexus dealer said to send it here:

Mr. Whizard Technical Services - Instrument Cluster Repair, Speedometer Repair, Odometer Repair and Digital Dash Repair

Turnaround was less than a week, and it was only a few hundred bucks. Everything has worked fine since the repair ~18 months ago.
I highly recommend them.

Good luck

Block

What year is your truck?

 

[agaisin]

what year is your truck?

2005 lx470.

As I noted in an earlier post, there's a TSB for 2004 model Prius, Highlander and LCs for http://www.vfaq.net/docs/TSBs/EL002-05.pdf. However, the issue with the MFD was (supposedly) fixed for 2005+ models.

Also, the TSB isn't detailed enough for me to know whether my symptoms really are the same. The symptoms you see on the screen are the same (external system is not connected, check the air conditioner connection, audio off, etc). However, in my case, NONE of the devices showed as connected in the service check mode's lan monitor, and the nav isn't ejecting the dvd (no power or nav ecu failed?). My impression is that with the TSB, the nav ecu would be ejecting dvds and working properly, but the MFD has all the symptoms. In this case, I am hoping that a wiring harness or connection to the nav ecu is causing everything else to fail but i don't understand enough to know if that makes sense. DI-1675 in the FSM (AVC-LAN Circuit Description) says:
"...
Multi display is connected between navigation ECU and radio receiver assembly. The navigation system has
the structure that makes it impossible to communicate without navigation ECU, multi display or radio receiver
assembly."

I am hoping that means that failure of the Nav ECU means nothing else can communicate to the MFD, but I may be reading too deep into it. I believe I've got to take the passenger seat out to really get access to the connections on the nav ecu and take it out but I don't have the time for that or for the full on connection by connection and device by device diagnostics myself this weekend. My truck's going to an independant shop on Monday so I guess I'll see what he comes up with in his diagnostics and take it from there.

 

[agaisin]

Well - my trusty mechanic had my car this week to do diagnostics. He found that power wasn't reaching the nav ECU due to a crappy satellite or ipod adapter install (they extended some wires by twisting them together and some had come apart). We believe that just happened while taking the unit out. After he verified that all devices were ok (continuity and voltage), his conclusion was that there must be a problem with the MFD and I needed to replace it.

I got my car back yesterday. Assuming that the MFD malfunction was the same as the 04 models, I found a couple sites (for prius) that show the defect in the circuit board for the 04 models, and how to solder it. I got some solder supplies expecting to be able to fix it but when I opened up the MFD, I looked under magnification at the notorious "pin 60" (I believe it's where the AVC-LAN communicates through the MFD) and couldn't find any sign of a bad solder job - it looked clean and in tact. So I called Mr. Whizard who is known to fix these issues and he directed me to try and flex the connections/board to see if I could get intermittent connectivity, to no avail. He said he'd pass b/c he didn't think he could fix my issue if it wasn't pin 60 and without my car to do further diagnostics.

So now I go back to trying to figure out what else (other than the MFD) could cause this issue, and found a few possibilities. Many talk about this issue after having an aftermarket device like VAISTech installed. Mine's been working fine for 3 months. I saw some complain about faulty wire harnesses, etc, so I decided to try putting things back together again minus the vaistech.

This time I did 2 things, not sure 100% which did the trick:
1) cleared the service check mode error codes
2) rather than just connecting the MFD, I connected the MFD and the radio head unit and the ABS (?) connections on the back of the MFD. This was b/c I remember the indication from the service manual (quoted in previous post) "The navigation system has the structure that makes it impossible to communicate without navigation ECU, multi display or radio receiver assembly."

This time, the MFD responded by trying to load the nav dvd, gave me back my climate control, etc.
I still don't have xm or ipod working (need to be reprogrammed I think?), and I have a new problem with the NAV ECU saying System Loading but it keeps saying that and never stops loading....

Just wanted to update ppl in case they have similar issues now or in the future. Looks very unlikely that the MFD in an 05+ would be failling. If you get told that, I'd question it and look into it more if you can. If I followed the advice of my dealership and mechanic thus far, I'd have shelled out for a new nav ecu and for a new mfd and it still wouldn't have worked

My mechanic definitely did solid diagnostics though and I owe him big time b/c he also didn't charge me even though he worked on it all week! He identified that bad wire connections that i never would have found.

 

[e9999]

very impressive detective work, Sir!
you got in there much deeper than most/all here have ever done!

good tech. Buy him some cold or hot beverages...

(for what it's worth and likely not relevant to your issues here, but I did have some trouble recently with a circuit board on my DD and all the solders did look fine but after I resoldered them all (didn't know which one was bad) by reheating everything worked again. So a visual inspection may not reveal all soldering problems.)

 

[agaisin]

Well - just got back from my test drive and glad to report I can finally put this behind me.

When I left off in last post, I had gotten the MFD working, but XM, Ipod and Nav and Bluetooth were not working. I realized that the XM and Ipod weren't working b/c I didn't put them back together properly (I inadvertently kept the vaistech devices out of the 'loop' instead of b/w the car's radio harness and the radio head unit).

The Nav was a real problem though - it kept saying system loading in a loop (it was rebooting after each attemp). I took it to the mechanic/technician hoping he could 'reboot' it. He disconnected the battery for 10-15 minutes, but when he was done with it I was back to the external system is not connected, and the nav was clicking and wouldn't eject the disc. He asked me to come back when he had more time...

At this point I took it home, took out the nav with the thought of rebooting it (hard reboot by taking it apart and there's actually a reset button that needs to be held down for a few seconds). Tried that, and then stupid me decides to try and pull the dvd out by force - I got it out, but also broke an internal piece and damaged the '05 dvd. SO, I can't say whether the reboot would have worked or not, but I knew I needed a new Nav ECU.

Luckily during my research for the MFD replacement I didn't need, I found a great used Lex/Toyo parts guy named Gus Mancy and he supplied me a replacement Nav (the part is interchangeable with many other toyota and lexus models so instead of paying 4k from lexus parts or 2k from the dealer for refurbd parts, it was ~500 including the '05 DVD).

Anyhow - everything's working fine. Btw, the original replacement part was 86841-50090 but the part I replaced with is 86841-0E010. I was nervous but it works fine.

The past week while I was waiting for the part, I've been driving around with the nav completely removed (kept the abs connected). First, my assumption that nav/mfd/radio all need to be connected for avc-lan is obviously false. Maybe mfd/radio need to be connected, but nav definitely didn't need to be connected - a/c and everything else except bluetooth and the map/dest/display buttons on the mfd worked fine. A few things I noticed - the bluetooth would show it connected and would popup the connection screen as if it were working, but the sound didn't pickup without nav connected. Also, the voice command button/function didn't work without nav. Also, and this took me a day to connect the dots, the driver's side lower speaker didn't work without the nav connected.

Anyhow, hope this helps someone else save some dough. Lesson learned is that while it's possible that your expensive MFD or nav fails and needs to be replaced, good diagnostics should be performed first and if a part really failed you may be able to get it repaired (I know of at least 2 places that repair the MFD) and if you can't or don't want to repair it you can get used parts (some of the used parts suppliers have warranties).

 

[RyanBuckner]

IS this problem fixed with a new display unit ?

 

[agaisin]

IS this problem fixed with a new display unit ?

Take a look at the full thread. In my case there was a wiring issue and the nav unit had to be replaced, but the MFD (display) itself did not need to be replaced. Are you having issues? If so - what are you seeing/experiencing? Do you have an '04 (iirc the 04's had a documented TSB issue with the MFD).

 

[n55luvr]

Excellent info agaisin.

I just picked up an 04 LC and 5 days into ownership (this morning actually) I got the 'External system not connected, check AC, Audio Off' messages.

The MFD was still presenting some data but my Climate display was dead (below MFD screen) and most of the buttons on the right of the screen were nonresponsive. At one point everything went dead but I could still turn the radio on and off via the knob. But then about 5 minutes later some info loaded to the Display screen, so it was reading things like current MPG, Range etc. When that happened Nav would still not work but the Climate info came back and I did have control of that. I have yet been able to get Nav to work again though. Makes me wonder if this is related to pin60 and a bad solder. I could see that causing intermittent issues.

So can I inspect my pin 60 easily? Assuming it's on the back of the MFD somewhere?Also, per the TSB for the 04's I'll check the TX +/- pins and make sure they are all seated correctly.

Also, I was going to give Mr. Whizard or possibly Gus Mancy (you have his contact info you could PM me?) a call and see what they said.

 

[SWUtah]

So the problem was not with Lexus quality control or reliability but with someone that modified the LX and "caused" a problem. Glad you figured it out.

 

[agaisin]

So the problem was not with Lexus quality control or reliability but with someone that modified the LX and "caused" a problem. Glad you figured it out.

SWUtah - if you're directing the question at me, I'd say there was a problem with Lexus qc or reliability arguably on multiple fronts:
1) the nav ecu shat the bed by getting stuck at system loading and wouldn't eject dvd. (Yes I tried to force the dvd out and caused more damage but the nav ecu needed to be replaced either way)

2) there was a wiring issue that the indie mech found. Even if it was caused by the aftermarket satellite install, that install was done by the lexus dealership.

In my view the dealership and their work also is a reflection of lexus quality and reliability. Their install was not a quality one - either they caused damage during the install or in very least did crappy work on the install (didn't solder wire connections which led to the wiring issue).

3ish) I could go on about other dealer related lexus qc and reliability issues - where they misdiagnosed, didn't try to diagnose, ignored my complaint and told me not a problem only to find out they didn't even try to reproduce, where they (likely) botched my car's dealer-installed overhead dvd install. And hey there's a known tsb for the mfd's pin 60 solder quality, and we can go on about other parts known to have issues.

Anyhow not trying to sound bitter, just wouldn't conclude as you did from reading my posts on this topic. Thanks for the stroll down memory lane, my my ownership has been quite an experience. I can say despite any issues i've experienced i am not aware of any such thing as a trouble free car - as far as car troubles go i wouldn't complain. i've enjoyed the journey and the issues haven't been catastrophic. i've never been stranded although that's more likely because i avoid my car's battery drain problem by permanently keeping my second row lights off and by using the priority start battery protector otherwise i probably would have been stranded on many occasions and would have sold it already. Root cause is likely a botched lexus dealership overhead dvd install (long bf i owned the car). Also the dealership has had multiple opportunities to troubleshoot the problem but has never been able to pinpoint or resolve the issue and yes i've paid the diagnostic fees and whatnot.

That reminds me of my rear third light gasket leak - believe dealership couldn't reproduce or fix but indie mechanic did and replaced with an additional aftermarket gasket to avoid future leaks. Another oem part issue and dealership tech/quality issue.

I'll stop there - not b/c i can't think of other part problems or dealership complaints but b/c i'm tired (don't get me started on ahc system or my most recent dealership fail with a noise they didn't even try to reproduce but claimed they couldn't reproduce without trying - man i hate the whole service advisor concept - at least if there's anything technical i'd rather speak directly to the tech so we don't have the miscommunication or lack of communication that happens with an extra layer of service advisor middleman bloat. I get it by i also get the problems with it. Enough for the night. Yes i do still have love for the lx470 - moreso now that i swapped out the ahc for oem suspension one less headache for long term ownership/maintenance.

 

[SWUtah]

So on this issue if your LX would of been left alone and kept as it came from the factory you would of never had a problem. Sounds like when it comes to trouble shooting your Lexus dealer should hire you. Congrats on finding and correcting their mistake.