Model 3 MCU on the bench

[FoxIrate]

Hello folks!

After I messed a bit with the Model S conputers, being unable to redeploy and figuring out that my IC is broken I decided to go for a Model 3 Unit.

Currently it's not up and running as I'm running into some problems...

First of all I have to wait for the cable that connects screen and MCU since my self made wiring is probably not good enough, was wondering if someone had a pinout of that connector. The Tesla one ain't telling me what I wanted to know (possibly hooking the screen to my laptop)

Second of all: The board seems to behave a little weird. When powering it without screen multiple LEDs start flashing. Same ones as I saw on reddit before. I then waited. Second LED next to the screen connector flashed really quickly and then stayed off. In videos it stayed on and showed video output. Might the board be damaged? It's also missing the LTE chip, SD Card and SIM so I'm not sure if thats connected somehow.

Heres a picture of both pieces on my desk:

Don't mind the weird wiring. Was testing something.

I hope the board isn't dead and people are interested in this project!

 

[Shelburne]

I'm not a computer geek and would never attempt doing something like this, but I would like to know, just out of curiosity, why you're doing all this. What sort of improvements do you anticipate?

 

[FoxIrate]

I'm not a computer geek and would never attempt doing something like this, but I would like to know, just out of curiosity, why you're doing all this. What sort of improvements do you anticipate?

Well, first I just wanna understand how that stuff works better. Like how does the computer react to different signals and stuff. And I also then want to see, where do we have capabilities that aren't used to their full potential.

In the end effect, I also want to mess with it and possibly turn it into some sort of gaming rig as I've done with other gauge clusters before

 

[FoxIrate]

Well, it's been a while.

I am one step closer to getting it to boot. Screen cable is hooked up and that onr LED stays on. I do still not get anything on screen though.

On a video I saw the two leds next to the screen connector stay on all the time and the power leds blinking rapidly. Here the power leds blink slowly and every now and then one of the screen leds turns off and comes back on (the one that stayed on before). I am guessing it's stuck in a bootloop?

I am missing the SD-Card and SIM so maybe thats an issue? Ethernet is locked as far as I know so I can't really set any values :/

Anyways, heres some pics

Full setup

Screen LEDS

Power LEDS

 

[robinyru]

Well, it's been a while.

I am one step closer to getting it to boot. Screen cable is hooked up and that onr LED stays on. I do still not get anything on screen though.

On a video I saw the two leds next to the screen connector stay on all the time and the power leds blinking rapidly. Here the power leds blink slowly and every now and then one of the screen leds turns off and comes back on (the one that stayed on before). I am guessing it's stuck in a bootloop?

I am missing the SD-Card and SIM so maybe thats an issue? Ethernet is locked as far as I know so I can't really set any values :/

Anyways, heres some pics

Full setup
View attachment 816090

Screen LEDS
View attachment 816091


Power LEDS
View attachment 816093
View attachment 816094

There is a serial debug port on the board. You can connect to it and check the output.

 

[FoxIrate]

Here we go! It's running!

 

[robinyru]

Here we go! It's running!
View attachment 862070

Cool. What resolved the display issue? I have a model 3 MCU with edid issue. It keeps looking for an edid file which seems missing.

 

[FoxIrate]

Cool. What resolved the display issue? I have a model 3 MCU with edid issue. It keeps looking for an edid file which seems missing.

Hmm thats weird. Well, it turned out that my display cable had two data lines connected wrong (because I was lazy and just bought a BMW one). In the meantime I also figured out that the MCU I originally had was water damaged and thats why it wouldn't display anything. So got a new MCU too.
I do remember that the other MCU said something similar when checking the output tho. Didn't look at the output here. I recommend to check your cable if you were lazy like me lol

 

[robinyru]

Hmm thats weird. Well, it turned out that my display cable had two data lines connected wrong (because I was lazy and just bought a BMW one). In the meantime I also figured out that the MCU I originally had was water damaged and thats why it wouldn't display anything. So got a new MCU too.
I do remember that the other MCU said something similar when checking the output tho. Didn't look at the output here. I recommend to check your cable if you were lazy like me lol

Thanks a lot for sharing the details.

 

[Francesco58]

Hi everyone! Good job to FoxIrate and I wanted to ask him, since I have a Tesla Model 3 tablet and mcu too, if he can show which pins he connected!

 

[FoxIrate]

So, further updates to this entire thing. My screen cable decided it wants to break, I then proceeded to buy a Model 3 Harness, titled as "Dashboard Harness" on eBay. From that Harness I extracted a cable which had a part number attached, redirecting me to the this. Part number is 1091280-00-C.
However upon connecting this the only possible way around the MCU just boots to a certain point and then turns off? Not sure what to think of that

Hi everyone! Good job to FoxIrate and I wanted to ask him, since I have a Tesla Model 3 tablet and mcu too, if he can show which pins he connected!

Yeah sure. Connected power according to this down here.

 

[Francesco58]

Thanks, I'll let you know if I have any updates on the situation and/or if I need further help. In the meantime I can tell you that even my 2019 Model x mcu shuts down after a while, I'm doing some checks but I'm starting to think it's normal, it probably goes into some kind of safe mode or idk

 

[FoxIrate]

Thanks, I'll let you know if I have any updates on the situation and/or if I need further help. In the meantime I can tell you that even my 2019 Model x mcu shuts down after a while, I'm doing some checks but I'm starting to think it's normal, it probably goes into some kind of safe mode or idk

Yeah probably, weird thing is that the BMW cable with flipped data lines and power lines worked and the factory cable does not at all

 

[gabrl123456789]

Hi, i wanted to know if i give power only to the pins 4, 5 and 6 the MCU starts or i have to connect all the pins?

 

[fishpepper]

Has anyone messed around with a HW3.0 MCU?
I just bought a used one and will start investigating once it arrives.
Right now i am missing the center screen as they are quite expensive...
My current plan is to either connect a generic HDMI monitor in front of the FPD-Link serializer or to use a combination of FPD deserializer and lvds to hdmi converter... Or does someone have a good source for cheap screens (can be scratched/partially broken).

 

[fishpepper]

Yeah probably, weird thing is that the BMW cable with flipped data lines and power lines worked and the factory cable does not at all

The power lines are swapped on my BMW cable as well. But that's easy to spot and fix: Do a continuity test on both pins on mcu and touchscreen to ground, then flip vcc+gnd on one side to match your readings. Never ever connect the cable if you are unsure -> The touchscreen will probably release all it's magic smoke and stop working!

But now i am stuck, my screen does not show anything even though i can ping my mcu.
When looking straight onto the cable my bmw connection (after fixing vcc) looks like (probably wrong):

[+ - ] [+ -] or bl bl or gr br br gr

I assume that the differential pairs of the serdes are messed up

Can someone with a working/stock tesla cable measure the pinout?

 

[FoxIrate]

The power lines are swapped on my BMW cable as well. But that's easy to spot and fix: Do a continuity test on both pins on mcu and touchscreen to ground, then flip vcc+gnd on one side to match your readings. Never ever connect the cable if you are unsure -> The touchscreen will probably release all it's magic smoke and stop working!

But now i am stuck, my screen does not show anything even though i can ping my mcu.
When looking straight onto the cable my bmw connection (after fixing vcc) looks like (probably wrong):

[+ - ] [+ -] or bl bl or gr br br gr

I assume that the differential pairs of the serdes are messed up

Can someone with a working/stock tesla cable measure the pinout?

Yes The VCC and GND lines are swapped. I knew that and swapped it. You do need to switch some of the data lines though as these don't match either. However mine is a mess so I can't really provide you help there.

 

[fishpepper]

Thanks. I got hold of the display datasheet with the pinout on the display connector (funy sidenote: its not made by tesla but it rather looks like it is a generic display you can buy). In addition i figured out the mcu connector pinout by tracing the lines from the serdes chip to the port.
I needed to switch gr<->bl and br <-> or to match the pinout.

Now my screen backlight turns on but nothing happens after that. According to the screen datasheet the backlight only turns on when there is valid data on the lvds connection.
However, tapping/touching the screen does not change anything.

Once i find time i will document the pinout somewhere. I bought an original cable directly from Tesla which has the same pinout but this shows the same behavior. The cable is actually quite cheap (25 Euro) and you can request the part by opening a service request in the tesla app. It only took 1 day to arrive.
I can see the ssh port and 8080 on the mcu open. 8080 shows some test ui, ssh rejects my connection (expected as i do not have the proper keys)
Right now I am stuck...

I did some looking around at the sd card content... Some logfiles and some data. I was able to extract the VIN and some GPS coordinates most likely before the crash (still in hex, needs conversion to lat/lon).

 

[FoxIrate]

Welp, I accidently shorted my MCU Power connections and now it won't start up all the way before completly loosing power :/

 

[XSTAGE]

Hi, could you help with the mcu power wiring diagram?