Android head unit (issues and solutions)

[Jarninho]

After working with 2 different Android Head Units and making pretty much every mistake possible I hope this write up can help others save some time and frustration... For clarity, this is about the units in the center dash, just above the climate controls. Not the CIC type units. I still have the original BMW Business radio. Car didn't have bluetooth from factory.

I have a 125i which I bought summer 2020. It came fitted with an Android Head Unit. It was a PX3 MTCD version. Terribly slow and just wouldn't work properly. The steering wheel controls never worked and the dashboard would switch to imperial and metric units at weird times. Also it kept resetting the clock of the car. Just plain weird stuff. I put a new rom on it (Malaysk, see xda forums) which made the unit a lot faster, and tried fiddling around with different MCU's, but I never could get the damn swc to work or the clock correct. So I pulled the plug on a new unit. I looked at Pioneers and Alpine, but they were very expensive for wireless Carplay. And they would sit lower in the dash and have no physical buttons (I like a round volume knob). I went for an Aliexpress ZlToopai 8 core PX5 Android head unit. $ 250 shipped.

It came with a slightly different wiring harness and a different label on the CANBUS controller than the PX3. Swc worked right off the bat. Great! New problem, damn thing wouldn't remember it's settings. Only for short periods of time. I think the PX3 also had that, but since I had so many other frustrations I tossed it out before being able to notice. So I connected the long yellow wire to fuse 2 of the fuse box behind the dash. I put an extra fuse between the yellow cable and the fuse box (didn't have a fuse tap). It worked. The unit remembered its settings and pretty much everything worked. I hooked up a Carlinkit Wireless Carplay adapter ($40) and that worked too. Wireless Carplay completely automatic without having to take my phone out of my pocket. Brilliant.

All was well until we entered the 2nd lock down in the fall and I didn't use the car so much anymore. After a week the battery was dead. Recharged it and after a few days it was low again. I also got a fault message in the dash. The image where you have to jack up the car. With the press of the left stalk I was able to get a CC-ID 415 message, which indicates a parasitic battery drain fault. CC-ID 415: 'Battery discharge rate high'. I charged the battery, and hooked it up with a multimeter in series to measure amps. I pushed the lock on the truck in so the car thought it was closed and would eventually go to sleep. This takes about half an hour for my car. After about a minute it was at 0.7 amps, and after half an hour at 0.3. Still way too high. It stayed there.
The radio is the only aftermarket thing on the car so that was the prime suspect. I unhooked the yellow cable from the fuse box and the amps dropped. Bingo. Took out the radio from the dash and looked at the wiring harness. Turns out the yellow wire going to the fuse box is connected to the radio, but also to the canbus, and to the iso connector from the car itself. So basically I was just putting 12v into the BMW connector all the time. Normally the iso connection gives 12v, but not when the car is asleep, which is why the radio loses all its settings and you need to connect the yellow cable to the fuse box. But I was putting 12v into the BMW iso connector at all times. Another thing I noticed was that there was a quick connector on the yellow wire going into the BMW iso connector. Because the unit came without any instructions I never figured out I had to unhook the quick connect on the yellow wire before hooking up the long yellow wire into my dash! Only when you figure it out, it's easy to understand...
Unhooked the yellow wire from the iso connector, tested it overnight and all was well. 0.03 amps or so. Haven't had any battery drain issues since.

But now the software. The Android Head Units apparently come with some variances. I'm not sure how much difference there is between a Carnaviplayer, Xtrons, ZlToopai, Belsee etc. Wouldn't be surprised if they all came from the same factory in the end, but it's a bit Wild West out there... Most common units are MTCD. My PX3 unit was. However PX3 only goes up to Android 7 (and PX3 is sloooow). My PX5 came with Android 10, which is actually a fake. It's just 9. But my PX5 unit was no MTCD, but S32F0. No idea why, but it's not the same. So all those nice custom pieces of software couldn't be used. Why would you want different software? Well my bluetooth wasn't working properly with my OBDII connector. However about a month ago on the XDA forums a new rom came out (Malaysk lite) and this solved the bluetooth problem. Unit is now also rooted meaning I can do more with it if I want (I don't).
I installed the Agama Car Launcher through the google play store (cost less than 2 bucks) which is what Belsee uses. When I'm not using carplay I have the nice BMW logo in the center and the whole thing looks very factory like.

It's now been working perfectly for a while. If it got stolen, I would get pretty much the same Android unit. I am an Apple user, and hated every minute of fiddling with this unit until it worked. But now that it does work, it's brilliant. I would however try to get an MTCD unit instead of an S32F0 (if it excists for our car!), although with the custom rom it's not a real issue anymore.

FM radio stinks by the way. There is hardly any reception even though in my area there are lots of radio stations. But I put in a DAB+ module (taped the module behind the right A pillar so you only see a little bit of the antenna which is barely noticable) and it works great. I understood the BMW rear window antenna needs power ,but I tried a few different connectors and even put 12v on it but never got it to work properly. This was the same with the PX3 unit.

What I would need to do is put the mic that came with the unit up with center mirror. I now use the mic from the unit itself which isn't great. I hope that one is a bit better.

My PX5 Unit:
ZlToopai Octa core.
Wiring harness with long yellow wire and able to disconnect yellow wire going into the BMW connector.
CANBUS unit label: JY 20181213 For BMW E90/X1 (< works properly)

My PX3 unit:
Witson S190
Wiring harness without long yellow cable
CANBUS unit label: BMW-BG-04 For: Old BMW 320i (< doesn't work properly with E82)

[G3min1]

So my question to you would be with the yellow cable you tapped into your fuse box.

I currently have an Xtrons Andorid Unit and I do not have the yellow cable connected to anything. My unit remembers my stations and everything. I just changed an option in the settings to say "remember."

I assume the yellow cable is there for a reason so I want to connect it but i'm confused as to where it should go.


You said "there was that there was a quick connector on the yellow wire going into the BMW iso connector. Because the unit came without any instructions I never figured out I had to unhook the quick connect on the yellow wire before hooking up the long yellow wire into my dash! Only when you figure it out, it's easy to understand... Unhooked the yellow wire from the iso connector, tested it overnight and all was well. 0.03 amps or so. Haven't had any battery drain issues since."

In this thread: https://www.1addicts.com/forums/show....php?t=1640497
They mentioned they used a mini fuse tap to connect the yellow wire in the black box spot.


So where did you end up connecting it?

[Jarninho]

Originally Posted by G3min1

So my question to you would be with the yellow cable you tapped into your fuse box.

I currently have an Xtrons Andorid Unit and I do not have the yellow cable connected to anything. My unit remembers my stations and everything. I just changed an option in the settings to say "remember."

I assume the yellow cable is there for a reason so I want to connect it but i'm confused as to where it should go.


You said "there was that there was a quick connector on the yellow wire going into the BMW iso connector. Because the unit came without any instructions I never figured out I had to unhook the quick connect on the yellow wire before hooking up the long yellow wire into my dash! Only when you figure it out, it's easy to understand... Unhooked the yellow wire from the iso connector, tested it overnight and all was well. 0.03 amps or so. Haven't had any battery drain issues since."

In this thread: https://www.1addicts.com/forums/show....php?t=1640497
They mentioned they used a mini fuse tap to connect the yellow wire in the black box spot.


So where did you end up connecting it?

I think I saw that thread when looking for a solution. They seem to have the same issues as I had. The pictures are helpful though as my unit is built in and I didn't take pictures of the installation... I put the yellow cable on fuse #2. See the arrow in below image.



In that thread you can also spot the quick connector you need to unhook. See the arrow near the yellow cable. If you don't unhook it, your car doesn't go to sleep, because you are putting 12V in the BMW system. It's the issue described in post #13.



I also have the memory setting in systems turned on, but it doesn't work for me. I don't use FM radio so I am not sure about that, but without the yellow wire connected my EQ settings reset every time and my Carplay adapter needs to get permission every time.
However, if it works fine for you now, why try to fix it? If aint broke....

[G3min1]

Originally Posted by Jarninho

I think I saw that thread when looking for a solution. They seem to have the same issues as I had. The pictures are helpful though as my unit is built in and I didn't take pictures of the installation... I put the yellow cable on fuse #2. See the arrow in below image.

In that thread you can also spot the quick connector you need to unhook. See the arrow near the yellow cable. If you don't unhook it, your car doesn't go to sleep, because you are putting 12V in the BMW system. It's the issue described in post #13.

I also have the memory setting in systems turned on, but it doesn't work for me. I don't use FM radio so I am not sure about that, but without the yellow wire connected my EQ settings reset every time and my Carplay adapter needs to get permission every time.
However, if it works fine for you now, why try to fix it? If aint broke....

Oh I agree, however I have a different problem where from time to time when the car starts up I have no audio. Then when I turn everything off (key out), and then start the car back up, I have audio again. I assume its the head unit going to sleep and not having power so I assumed the unattached yellow wire was the culprit.

[tankertoad]

Is the money saved vs. mainstream head units worth all the trouble?

[g0atb0y_71]

I have a similar unit but a slightly different problem. My car won't go to sleep at all.
I have sound it all works fine until I shut the car off and lock it.

The start button then lights up and i hear the actuator. This process repeats every few minutes.

I do have the HiFi system so during my testing the two fiber connectors are disconnected so perhaps an open loop is causing the issue?

update:
on advice from the seller I connected the main power line to the AC outlet circuit. The stereo shuts off and the car goes to sleep.
however, this does mean I have a cold boot each time I start the car. I suspect if I tap fuse #2 with the 2nd yellow cable I'll be back to square one with the car not sleeping since the 2nd yellow is spliced into the main power line in the harness.

[g0atb0y_71]

Originally Posted by g0atb0y_71

I have a similar unit but a slightly different problem. My car won't go to sleep at all.
I have sound it all works fine until I shut the car off and lock it.

The start button then lights up and i hear the actuator. This process repeats every few minutes.

I do have the HiFi system so during my testing the two fiber connectors are disconnected so perhaps an open loop is causing the issue?

update:
on advice from the seller I connected the main power line to the AC outlet circuit. The stereo shuts off and the car goes to sleep.
however, this does mean I have a cold boot each time I start the car. I suspect if I tap fuse #2 with the 2nd yellow cable I'll be back to square one with the car not sleeping since the 2nd yellow is spliced into the main power line in the harness.

I moved to slot 2 and it all seemed good but after a day or two I started seeing the CC-ID 415 error. I've moved back to slot 8 (12v outlet) and no longer get the error but the stereo needs to boot each time I start the car.