Multi Function Display failure

[PJD]

Hi again - sorry I have yet another query (sure they'll be more) however this is more serious, - really hoping for some assist if possible (I have only just brought this car privately).  I have intermittent problems with the MFD on my 04 LS430.  It suddenly stops working & renders the air-con, sat-nav, reversing camera, everything which is controlled by the touch screen and surrounding buttons - useless.  The radio can still be controlled by the radio unit however.

When this happens I receive messages on the MFD: "external system not connected", "check connection of the air conditioner", - and none of the buttons work.

It can stop working for half and hour or so, and suddenly start again, - or when I turn the car off for 5-10 minutes sometimes the problem resolves.

I read a suggestion to check that the connections going into the rear lights weren't corroded, due to a possible leaking gasket, but both the inside of the rear lights look fine.  I have tried disconnecting the Battery for a while, and have also removed the wood trim and radio to check the connections (I haven't removed the MFD unit yet, however).  I have checked some of the fuses in the cabin, which look fine, but surely if it was a fuse problem, it would occur constantly not intermittently?  The Battery is OEM & all other electronics work fine, so I don't think it's due to this (but of course I could be wrong about any of the above...).

I have searched high and low on the net, and there are a number of people (mostly in the US) who have had this problem, but I cannot find a clear solution, however there seems to be a common issue with 2004 models in regards to the connection to the MFD circuit board which fails, - so, I could contact a MFD repairer, however, how can I be sure that this is definitely the problem first?

Any constructive guidance at all really would be greatly appreciated in regards to how to proceed to get this sorted on my new car! :) :( 

 

[black400]

It might be a idea to talk to a Lexus dealer， you might be lucky if it  is common enough.

I will probably require a full Diagnosis 

I wish you luck ， electric s are a pain in the harness

[steve2006]

Intermittent faults are a pig to trace but it may be an idea to release the display enough to gain access to the connectors and then give them a wriggle also lightly tap the unit to see if you can make the fault appear.

Since the introduction of lead free solder electronics seem to have more reliability issues.

 

 

[Bluesman]

8 minutes ago, steve2006 said:

Intermittent faults are a pig to trace but it may be an idea to release the display enough to gain access to the connectors and then give them a wriggle also lightly tap the unit to see if you can make the fault appear.

Since the introduction of lead free solder electronics seem to have more reliability issues.

 

Ah the smell of lead and flux wafting up your nose, those were the days.

 

[PJD]

Thanks all. Lexus dealers weren't much help unfortunately.

I found this technical bulletin from Toyota which describes the problem perfectly:
http://www.vfaq.net/docs/TSBs/EL002-05.pdf

...seems a little coincidental that it's exactly the same symptoms, on the same year cars.  I have no idea how similiar these Highlander/Cruiser/Prius units are to the LS430, however, there is also a fix; it was down to a hairline crack in one of the connector's on one of the circuit boards (Pin 60)
http://www.techno-fandom.org/~hobbit/cars/mfd/

This outfit have also fixed many, so it's obviously a known problem, but they won't ship outside the USA unfortunately.
http://www.mrwhizard.com/Climate%20Control%20Repair.cfm

If I could determine that the Prius/Cruiser unit is the same as the LS430, I could at least advise a local firm, - I asked an eBay Lexus-parts dealer; he thinks the unit is a completely different design... shame if true, - as discovering a possible hairline crack in one of the many circuit board connections looks like a painstakingly long task, as the car electronic repair guys I have spoken to so far aren't familiar with this issue.

[PJD]

Sorted this ages ago, but forgot to update thread, - just in case anyone has the same, reasonably common, issue; - get in touch with Maple Audio in Bath, - they sorted it quickly and comparatively very cheaply - highly recommended, - has been working like a charm since :)

 

Problem was a connection problem with one of the integrated circuit boards

[Isaiah Douglas]

I’m having a similar situation with my Lexus. One day the MFD stopped working. I’m wondering if it is a blown fuse. I’m not exactly sure which fuse to look for if that is the problem. Also whenever I am driving I hear a constant beep. It’s the same beep whenever a door isn’t closed properly or if the oil is low. I am getting worried.