LX570 - replacing MMI ECU, need help!

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chipsterguy

chipsterguy

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Jul 19, 2016
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I've been having problems with the entertainment system on my 2010 LX570 since purchasing it used a couple of years ago. See my prior posts for more details about this issue, but basically, during the fall and spring as the temp transitions through about 40-50 degrees in the morning, my audio system goes nuts, randomly switching audio inputs, spitting out CDs, etc. LX570 Audio/Electrical Gremlins

Also, it is not recognizing my 5th Gen, old school iPod (which I still cherish for its amazing audio quality due to its Wolfson DAC). This Technical Service Bulletin addresses the iPod issue. http://www.revbase.com/BBBMotor/TSb/...dPdf?id=167576

So, replacing the old multi-media interface ECU with a new version will fix the iPod 5th gen problems I am experiencing. And, I suspect that this updated part may also address the weird behavior my audio system exhibits a couple of times each year.

Apparently, Lexus updated the ECU back at the time of the TSB (new revision of the PN), the PN (then and now) is 861A0-77010. It is located underneath the front passenger seat.

Has anyone changed this part before? Any tips on removing the old / installing the new ECU? Does the entire passenger seat need to be removed to change this part?

I would greatly appreciate any help!!
 
Good to know. Thanks for sharing this. Unfortunately I haven't experience in changing that computer.
Question for you. I have a Gen 1 iPod Touch that I haven't used in years. How is the DAC in that unit?
 
Gen 5 and 5.5 have this DAC.
 
Bump for advice...
 
Following - curious to see if the ECU fixes this issue as I have 2010 LX with same issue.
 
Wondering if the MMI ECU is in the same place on the Land cruiser - there are obviously many more of these on ih8mud.
 
Thanks to your post I pulled my old 1st gen iPod Touch out of a drawer and started using it as a “music server” in my car through the USB connection.
However something occurred to me regarding the discussion on the DAC. In this configuration, USB connection to LX, it will not matter what DAC is in the iPod as the USB connection supports digital music transfer only. What you will hear in sound quality is based on the DAC in the vehicle’s system. In my case it is the Mark Levinson Reference Surround which is actually quite remarkable for a stock stereo IMO.

I hope changing the ECU solves your problem. It’s a shame the previous owner didn’t have it warrantied under the TSB.
 
iPod's only send analog audio via the 30 pin connector. Transfers are digital, of course. But will not stream a digital playback signal. I suppose this is/was to clamp down on pirating - DAC -> ADC will always be somewhat lossy (some better or worse than others), ultimately degrading the fidelity of the audio. That is why the Wolfson DAC is so desirable, at least for me. It enables my Mark Levinson audio system to amply sweet, clean audio that's about as good as the method by which it was encoded.
 
Ordered & received the MMI ECU and hope to install shortly. Will post pics.

From what I understand, I may need to unbolt the passenger seat and tip back to get at the area under the seat where the ECU is mounted. Will also disconnect the negative battery terminal so as to not inadvertently trigger the seat air bags.

Anyone have experience removing the passenger seat? Any tips would be greatly appreciated before I get started on this project.
 
chipsterguy said:
iPod's only send analog audio via the 30 pin connector. Transfers are digital, of course. But will not stream a digital playback signal. I suppose this is/was to clamp down on pirating - DAC -> ADC will always be somewhat lossy (some better or worse than others), ultimately degrading the fidelity of the audio. That is why the Wolfson DAC is so desirable, at least for me. It enables my Mark Levinson audio system to amply sweet, clean audio that's about as good as the method by which it was encoded.
Click to expand...
I believe the 30 pin has both digital out and an analog out. The new lightening cables only support digital out. 30pin to lightening adapters are so expensive because they have a DAC chip in them for devices (think old 30pin docs in clock radios, etc.) that only operate on the analog signal.
Knowing that the ML system can connect to a newer iPhone through a lightening to USB cable and is getting a digital signal for it's DAC, I wonder how it handles signals from the older devices using a 30pin.
 
UCrazyKid said:
Thanks to your post I pulled my old 1st gen iPod Touch out of a drawer and started using it as a “music server” in my car through the USB connection.
However something occurred to me regarding the discussion on the DAC. In this configuration, USB connection to LX, it will not matter what DAC is in the iPod as the USB connection supports digital music transfer only. What you will hear in sound quality is based on the DAC in the vehicle’s system. In my case it is the Mark Levinson Reference Surround which is actually quite remarkable for a stock stereo IMO.

I hope changing the ECU solves your problem. It’s a shame the previous owner didn’t have it warrantied under the TSB.
Click to expand...
Hmmm, service bulletin?? can you elaborate or tell me where to find it? I'm curious since having same issue.

Thanks
 
I think that the source of many of the weird radio/receiver problems may be the ECU. I will report back once I do the install.
 
Any luck with this?
 
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