Bricked (I believe) CMU, able to replace?

87029 Views 134 Replies 51 Participants Last post by mihait, May 14, 2022

MazdaBadman

Discussion Starter · Nov 4, 2016

I tried to search for this specific answer but didn't see it. I was beginning to have touch screen problems on my 2014 Mazda 3 (out of warranty) with bose/navi/infotainment etc so I was going to try a firmware update. I was on 55.00.650 and I successfully installed the failsafe part of the 59.00.411. When I got back into the diag menu the touchscreen was dead so I couldn't enter "99" to begin the second part of the install. Instead of using the commander knob to scroll to 99 I stupidly held mute+nav to do a reset and the screen went black and never came back on. No Mazda logo or any backlight whatsoever, just radio playing in background.

I don't believe the bootloop recovery threads will help because it wasn't after a file modification that this happened, although I have had the touchscreen speed limiter and background pic modified for about 6 months with no issue. My display shows nothing at all. Please advise me if you think I can actually recover using one of these threads.

My question is I've found some replacement CMU's which match my part number (BHP1669C0 K2352) on ebay for a reasonable price used. With these used units, can I install this in my car and use it or will be locked by anti-theft code or some such thing? I just want to know if I'll be able to use one of these used units or will I need to buy a new OEM unit to fix this issue?

I'm just trying to do this fix myself without paying the dealer if possible!

Thanks for any advice!

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ASH8

· #2 · Nov 4, 2016

Sorry to hear about your issues...

I could be wrong, but I have heard of other issues with updating to NA_59.00.441 when owners have previously done mods to system.
From what I read any changes must be reversed/removed before V59 is installed.

I know this does not help you right now.

Not so sure about buying a used CMU as I know Navi gets locked to SD Card via cars VIN Number after 62 miles, don't know of a way to reset this (or heard of one), so what happens if you put in a used CMU?, I would think you would need the same cars SD Card, but what about VIN recognition via IC and PCM?

Please let us know how you get on.

oldfartwithamazda3

· #3 · Nov 4, 2016

Are you sure your warranty has expired. I'm under the impression that you have 3 Years/36,000 Miles, not unless you are over 36,000 miles already? If under, take it back to dealer under warranty.

Simon87

· #4 · Nov 4, 2016

Take it back to the dealer. Say you have some problem whit screen in your car. Sometimes when you start the car your screen was freezed and back to life in couple of minutes while you drive the car. And say that in the morning when you go to work its stuck completely... you didnt instaled mods if they asked you you dont know about mods... You cann try hard reset couple of times again like 5 times. try unplug your battery from car and unplug your both cable from battery and when you unplug them stick them together but they must not touching battery. leave it alone for 10 to 15 minutes and than plug both cable in battery. maybe this will help...

moses_lawn

· #5 · Nov 4, 2016

I have the same vehicle and my infotainment unit bricked to a blank black screen with only the previous radio station playing in the background.

I called the Mazda Connect support number and theyre aware that this is an issue and replaced it for me at no cost. I recommend doing the same.

Reactions: 1

MazdaBadman

Discussion Starter · #6 · Nov 5, 2016

Thank you for all the replies!

ASH8, thanks for bringing up the navi pairing issue. I believe you are correct as I have also been following the infotainment project thread where they discuss the 62-mile limit. Indeed the used CMU will likely not have a functional navi once installed in my car. Also as you mentioned, possibly other pairing issues may occur so maybe a used CMU is not a good idea.

oldfartwithamazda3, I believe my warranty is up but not sure. I do indeed have the 36,000mile/3-year warranty but I am currently at about 45K miles

I drive a lot haha.

Simon87, thanks for the suggestions. I have already tried many hard resets. Also, during my removal of the CMU to gain access to the part number, the battery was disconnected for a significant amount of time. Still no life

moses_lawn, these are my exact symptoms so hopefully Mazda will be helpful when I take it in to be looked at.

So, with all this information at hand I think this will be my plan:
1-I have a dealership appt on Thursday to find out "what's wrong." I will play super dumb and see if they will fix the issue.
2-If they refuse/try to charge me something unreasonable, I will likely order a NEW CMU (found for about $540) to avoid any previous vehicle pairing issues and hopefully retain navi functionality (I still have my navi SD card which is paired to my car)

Another question: has anyone ordered a used or new CMU unit and tried to install it in their car? What happened when you did?

I will absolutely keep my post here updated to tell everyone what happens! Thanks again!

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championway

· #7 · Nov 5, 2016

since you have still radio sound to hear and the part failsafe went with you 100%, its not hard brick. also you did modifaction before so you have the ability now to et this point.

just put the script of wifi enable on usb and go to procedure of SSH with putty only,
nothing more need just the 3 command to trick cmu to reboot

mount -o remount,rw /

mount -o remount,ro /

reboot

your screen will be back, and go back to yours pervious version.

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Reactions: 1

tarahumara

· #8 · Nov 5, 2016

I've replaced my cmu with the shielded one for wifi problems. It's super easy and I've used the existing original Nav SD card with the new cmu without any problems.

MazdaBadman

Discussion Starter · #9 · Nov 11, 2016

So I just got back from the dealership.

They looked at the system and said nothing about my modifications. The tech said he tried to 'reset' it but with no luck. He said the CMU "has a short in it and has failed and will need to be replaced." They quoted me $914 which obviously I'm not doing right now. So, it looks like a new CMU might be in my future. Found them online for about $540.

championway, I have tried the button combination nav+mute (or whatever it is) several times and it did not appear to reboot or fix itself. Do you believe that using the WIFI enable script and having it run those commands will have different results? If so, I will try later tonight.

tarahumara, thank you for this information! I'm assuming you purchased a brand new CMU unit or did you purchase a used one?

locoface

· #10 · Nov 11, 2016

I had the same issue bricked CMU they (dealer) replaced it my Nav is no longer working, they are going in circles to have me bring my SD card to fix it. They still can't figure out, got sick of it and just installed Android Auto and am using that for now.

vic_bam85

· #11 · Nov 11, 2016

Hi, you can try this to recover your CMU.

https://www.drive2.ru/l/452929522484904460/

Hope it helps

championway

· #12 · Nov 12, 2016

as i said your CMU not hard brick.. you are lucky that failsafe was went 100% if wifi dont come up then use putty as seriel as vic_ over this post russian tweek.

MazdaBadman

Discussion Starter · #13 · Nov 14, 2016

Unfortunately it looks like the system does not respond to USB scripts at all and also there is no activity from wifi. Sometime this week I will be trying the USB to serial direct line that vic_bam85 suggested. Hopefully I will have some luck! I'll be back with updates.

Reactions: 2

nick.biss

· #14 · Nov 16, 2016

Hi All,

Finally found the thread I've been looking for.

I am having the same issue; my screen has been blank since mid-September. Finally had a chance to take it in to the dealer and was told that the entire unit would need to be replaced ($1,100).

I'm interested to hear if you're able to resolve this problem.

-Nick

MazdaBadman

Discussion Starter · #15 · Nov 19, 2016

I am back with unfortunate news. Thank you vic_bam85 and championway for your suggestions but it appears my CMU is totally dead.

I set everything up just like it was in the Russian post provided by vic_bam85. I tried multiple times to connect the wires and made sure everything was correct. I got the USB to Serial adapter to install its drivers in windows fine, the chip in the USB reads as genuine (apparently there is a counterfeit chip problem) and putty sees the USB adapter on COM3.

With the car powered up, when I try to open a connection in putty, the windows opens to nothing but a solid green cursor. No login prompt. I though I read a while ago that sometimes the connection is actually active even though it doesn't SHOW anything. I tried typing in the root login and password but nothing. I even tried typing that in followed by the commands suggested by championway. I get no results at all. Still dead CMU. I think unfortunately it is just dead! RIP CMU!

So, unless someone has any other suggestions, I believe I will be ordering my new unit here in a few days. The PN from my unit is BHP1-66-9C0C. The dealership wrote on their quote the PN BHP1-66-9C0J. I will most likely be ordering from this website which is offering a unit with PN BHP1-66-9C0M, which apparently replaces all previous revisions A-L.

I will continue to update here to let everyone know how the new install goes! Of course if someone has last minute suggestions I'm all ears!

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championway

· #16 · Nov 19, 2016 (Edited)

i think the problem you have the adapter you use now .. you need to use (SINGLE-CHIP USB TO UART BRIDGE ) , íts cheap less than 6USD and it can be use always with dead circuit / mobile phone etc. to write command and also to transfer whole firmware / script

http://www.silabs.com/products/interface/Pages/cp2104-mini.aspx

MazdaBadman

Discussion Starter · #17 · Nov 20, 2016

Oh I forgot to mention I didn't buy the exact adapter that was suggested in the tutorial post. I bought this one. It uses the PL2303TA chipset. Do you think this adapter and chipset are compatible with the adapter you mentioned?

championway

· #18 · Nov 20, 2016

Yours Adapater driver Install could be wrong.

well, i cant tell if this adapter the correct one, of one reason.
you mentioned when you install its driver on your PC it show with you ( USB reads as genuine ) this should not be so

USB adapter should have driver as direct connect , this mean it should be listed at PC device manager / hardware under PORTS (COM & LPT ) ( winxp professional sp3 )

so Putty can communicated and show the text to you..

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MazdaBadman

Discussion Starter · #19 · Nov 21, 2016 (Edited)

Sorry for the misunderstanding I didn't mean the adapter shows up as a genuine USB device. With the adapter I purchased, the drivers also come with a small program which verifies if the control chip inside the adapter is a real, genuine chipset from "adafruit" (the company who makes the adapter). There are apparently counterfeit adapters floating around which to not work correctly. The program tells me I have a genuine adafruit chipset.

In device manager this adapter does in fact show up under Ports (COM & LPT) as "Prolific USB-to-Serial Comm Port (COM3)." I am using the drivers recommended by the manufacturers website.

Is there a way to tell if I have a good connection into the CMU besides putty successfully showing me a login prompt? Is there maybe a voltage I can check for on the green/white signal wires?

Or possibly the adapter I have is not capable of doing what putty/the CMU need?

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anderml1955

· #20 · Nov 21, 2016

MazdaBadman said:
Sorry for the misunderstanding I didn't mean the adapter shows up as a genuine USB device. With the adapter I purchased, the drivers also come with a small program which verifies if the control chip inside the adapter is a real, genuine chipset from "adafruit" (the company who makes the adapter). There are apparently counterfeit adapters floating around which to not work correctly. The program tells me I have a genuine adafruit chipset.

In device manager this adapter does in fact show up under Ports (COM & LPT) as "Prolific USB-to-Serial Comm Port (COM3)." I am using the drivers recommended by the manufacturers website.

Is there a way to tell if I have a good connection into the CMU besides putty successfully showing me a login prompt? Is there maybe a voltage I can check for on the green/white signal wires?

Or possibly the adapter I have is not capable of doing what putty/the CMU need?

What you can do is connect the adapter transmit and receive wires together (no CMU involved) and open putty. Anything you type on the keyboard should echo back to the screen.

1 - 20 of 135 Posts

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