More great info. BTW, I did read you whole first post (twice! ha).

Question about the volume issue:
Elsewhere I read that you should turn the volume to 100% with he PCM installed. You said you turned yours to 75%. Why didn't you do 100 and do you think it would have helped the volume issue improve even more? Also, how do you turn it up all the way without blowing speakers/your ears?

Wiring:
Is it 100% plug and play or do you need to do the typical tapping and splicing? I've installed several systems over the years but have never been very confident doing it, just kind of muddled through it...seemed to always work though...eventually

As to my PCM:
We made the mistake of getting a refurb from the dealer for too much money. It's the one failing now.
Everything works except the sound output with the radio only. The screen dims and brightens a little randomly. The sound does work intermittently when parked and the engine is just turned on. A few seconds later, no sound. Also, another weird symptom, that dimming of the screen is somehow connected to using the power windows. When I use the window, the screen either dims or brightens (can't remember which) and sometimes causes the music to come on. The sound DOES work with the CD player (when I can get that thing working since it's VERY picky about discs).

What do you think? Maybe a power delivery issue? I should probably just start by pulling the unit and checking all the connections. Where else should I check besides behind the HU?

 

​​​​​​​Dang, that looks amazing. Looks very factory. What unit did you buy?

 

Oh, also, as far as the parts list, you just buy the head unit, most adapter, and backup cam? That is the full list? What OBDII adapter did you get? What about the dual antenna connection?

 

 

My unit was a Android 7.1, PX3 chipset, 2GB ROM, 32GB RAM -- it was branded "Wondefoo" on Aliexpress. My delivered price a year ago was around $285. I separately bought a MOST box off eBay for around $85. The install was plug and play, although I did some minor splicing/soldering on the HU harness. I neither cut nor tapped any factory wires. I did have to drill a hole into the plastic well underneath the center grille on the dash so I could feed the GPS wire (and also a USB extension for a possible 4G GSM modem which I ultimately bailed on -- the phone tethering was cheaper/more convenient).

The technology has improved since then. You now want the PX5 chipset (faster than PX3) and get more ROM (4GB or more is better for caching apps) if you can. The RAM amount is a user choice as you can always add a bigger USB for music/files should you wish. This unit appears nice and seems to have a slightly bigger screen than what I bought: AliExpress HU It looks like you can also add the MOST box for $80 from that vendor (no experience/relation).

On installation, I did set the volume on the PCM at a "moderately loud" listening volume before removing it. I'm not sure how much that mattered, honestly. I suspect it doesn't matter much as the MOST box handles it all anyway. The HU comes with a single Fakra plug for the antenna. I later bought the double Fakra adapter off Amazon, but it didn't help -- my FM radio reception is reliable only for the strongest stations. Don E. posted the amplifier schematics on the "long Android thread" and identified that we need to give power to the various FM antenna modules in the Cayenne, else we wont benefit from the Cayenne's amplified diversity antennas (Discussion is: here ). I've not gone back to mess with this, but it should be an easy fix if you can figure out which wire in powers the antenna modules and just make sure they receive switched power.

If you look in the picture I posted above, you'll see on the left side where I routed the microphone. I pulled removed the thin trim piece between the steering wheel and the center console and fished it through there and stuck it back on the trim piece. You can also see the 4 small scuffs from where the metal tabs that retain the HU damaged the leather around the center console. Use some blue masking tape to protect those areas while you're doing the install to prevent that.

I'd previously installed a VW backup camera (per the now old school instructions on how to add one to the factory PCM). I hardwired mine which was a PITA. I used CAT6 and a video balun (like this: balun ) on both ends of the CAT6 to keep the wire I was running through the headliner and tailgate as small as possible. It works great, but it took extra time/planning to do it. I did splice power from the reverse lights in the RR trunk cubby (just in front of the RR tail light). That was the only modification I remember making to the wiring. In retrospect, I could probably have just kept it always powered from the license plate light that the camera replaced.

Regarding OBD/Torque, I used an ELM327 based unit off of Amazon. It needs to be bluetooth, but they're otherwise cheap and common.

 

That looks awesome Brainz - I think I am going to try that launcher too. I go back and forth between liking the stock style interface and the live wallpaper. But the good thing about the Android units, you can swap the whole UI easily. Btw it might be some work but you should be able to update the firmware on your HU to run 8.0, which might get rid of the connection issues. Seems there are many on xda that do this.

For setting the volume, I think the distortion was higher when I set it to 100% volume before unplugging the PCM so it choose %75 and called it good. But I don't know for sure. Btw, after waking the house up after turning it up I figured out to set it to a blank FM station first!

Natty, wrt your PCM, by the sound of it your amp is probably fine and it is just the PCM that is jacked. You could take it apart and see if a component is failing, but I'd guess just going ahead with and Android unit would probably work.

Morganmobile, I am really interested in the OBDEleven now, I had not seen this before. I carry a tablet and my VCDS cable everywhere; does the OBDEleven really do everything the VAGCOM cable can do? It sounds great if it does. Do you have to short the pins like with the VAGCOM? Thanks.

 

Just thought I'd mention, I took the time today to relocate the wireless backup camera transmitter from the outside of the metal rear hatch - originally I just stuffed everything inside the area that the light it replaced was, so it had to transmit through the steel of the lid. By popping off the inner hatch trim you can place the transmitter on the inside, and now the signal is 100% under all conditions. Easier than running a cable and the image is flicker free now. Power for the transmitter, the camera and the LED all come from the old lamp connector and works fine.

 

How does it trigger to only come on when in reverse?

 

Would love if you could post a pic of where you mounted it. Also, can you link to the camera wireless transmitter you bought? I can't seem to find the correct one.

thanks!

 

So it was late and I didn't take any pictures, but I found this image on the web, from a different year but makes the point. The red circle is where the wires come through from the camera outside on the back (below is the plug for the license plate light that you patch into for power). The green circle is where I mounted it. The interior trim is obvious removed here, but you don't have to take it all off, just the bottom 4 clips will give you enough room. It's really easy, when the trim is on there is a hollow in the foam that goes between the trim and the steel that it fits in perfectly. Then I just duct taped the wires to the trim to keep them in place.



I wouldn't get the exact camera I got because the screw holes are a few mm too far apart, but this is a link to the wireless transmitter here. Less than 10$, so if you don't like it just throw it out and run a cable. I power both the camera and the transmitter off the light plug, they use very little power.

 

So, we need to buy the transmitter set which has the trigger wire, and all of these Android head units have the trigger wire to connect onto?

 

I didn't realize there were different configurations! I just got the simplest one with no trigger or anything, like this:



You just plug the one with red and yellow plugs into your camera (video feed and camera power) and connect the coiled up black cord to power (from the rear lamp). For the receiver side, just plug the yellow video out into the RCA on the HU marked rear camera, and the power to the same ignition controlled power that you use for your HU. I suppose this means your rear camera draws power whenever the vehicle is running, or if your parking lights are on, but since it uses the same or less power than the light bulb it replaced, I don't think it is a problem. The head unit automatically switches to the rear camera when you put it in reverse.

One thing to consider (which I didn't) when choosing a rear camera is if it is hard wired to produce the red/yellow/green distance bars or not. I got one that did and they can't be turned off, and then I figured out that the HU can also put either the fixed color bars on the image for you, or the blue trajectory image that turns when you turn the wheel to show you where you are going to go. I would actually have preferred to get a camera that has nothing added to the image, because I would rather just have the trajectory overlay, and if I ever want the colored distance bars I can use the ones overlaid by the HU. But I guess some HU's don't have the overlay selection, and that is why some cameras come with them.

 

I have two Android 8.0 px5 units and I want to share the following issues.

On one I had the factory backup camera working for a couple days then it died. While troubleshooting I discovered a melted diode in the CANBUS decoder. I will first replace the CANBUS decoder. Replacement diodes can be purchased for $10 shipped but it looks like a tough solder job. On the other unit the factory backup camera still works fine.

On one I had bluetooth stop connecting and wifi will no longer turn on. This problem appears to be specific to px5 head units and is not unique to me. I ordered a CF-WU725B wifi+bluetooth dongle for $6.50 that I will try to plug into USB and see if it enables one or both. The issue began as intermittent (worked after turning car off and back on) but now appears permanent. I am still looking into it.

Without these issues (or if I get the issues sorted) I'd give these units two thumbs up.

 

@@Zakowsky
Which MOST adapter and CANBUS adapter did you use?
Can you link to them please?

 

The MOST adaptor I used was this one. The CANBUS adaptor came with the head unit and I don't see where you can buy it alone. But maybe write to them, they are quite accommodating it seems. The vendor is linked to on the MOST adaptor page.