Neopolymath

Hello, I hope everyone's year is off to a great start!

The basics: 2012 Cayenne Turbo. 60k miles. Recently purchased. Unknown if USB port was previously working. PCM version is 3.43. Completed PCM reset (handover/transfer). It has only spontaneously rebooted once but otherwise functions normally. Radio works. Notably, the aux port works. Bluetooth music streaming works.

After I took delivery of the vehicle, I noted that the 12v sockets in the cupholder and armrest did not provide a charge and the USB port did not function. I noted a blown fuse in right side slot 38. Replacing that fuse rectified the 12v socket issue as expected, but the usb port problem lingers. I think the usb port physically broke somehow. I'll outline what I've tried and noticed below. I attempted these things with the car running so it would definitely have full power instead of with just accessory mode where that might not be the case.

Flash Drives:
According to the manual, Fat32 is an accepted format and mp3s are fine too. I tried 3 different brand flash drives ranging in size from 4, 8, and 32 GB. I freshly reformatted them on Windows (I think one was done on mac). I added several old mp3s that I have. No other files on the drive. The PCM does not ever register that a usb stick was plugged in with blue text at the bottom, under source options, or under media options (like aux does next to disc). One jump drive flashes some lights for a few seconds and then stops. One flash drive continuously blinks. One flash drive never really blinks.

iPod:
Old iPod touch. I tried 4 different 30 pin cables. One or two of them are actual Apple cables not third party. These cables work in other vehicles and scenarios. It never registers that it is charging and the PCM never notes that the iPod is connected.

Android phone:
When I plug an S10+ in the phone pops up "Check your charger connection. Make sure the cable and charger are properly connected." The phone momentarily shows that it is charging but then it stops almost immediately. The phone and cable work fine outside the car.

Iphone:
When I plug an iphone 12 pro in the phone pops up with something like "liquid detected in lightning port or cable. disconnect and let phone dry". If I remember correctly, the phone shows that it is charging momentarily but I might be wrong. The cable and phone work fine outside the car. Interestingly, when I googled the exact error message it did note that this error message may occur if the cable and or charging port is not messed up. I also tried an older iphone and it wouldn't register a charge or give an error message.

My assessment so far says that clearly the usb port is not functioning (duh). The PCM appears to connect to a cable that runs to the port. That doesn't leave many potential culprits. I did not see any gross deformities or foreign bodies in the port. I did not see any signs of liquid infiltrating the area. The fact that none of those things work makes it clear it's not a device issue like a ton of the old threads on search show.

My plan is to use a magnifying glass to closely inspect the plug to make sure I didn't miss something like a piece of metal. I plan to use a USB port voltage and amp monitor to see if it is actually providing power when something is connected. After those two things, I plan to take out the armrest storage compartment to examine the connection between the cable and the port. I will try to confirm that the usb cable from the pcm is not externally powered by something else. I will see if I can find the part number of the usb cable and see if I can source it. Perhaps there is corrosion or a broken connection somewhere. It seems unlikely that the pcm is broken just in this one manner but I could be wrong.

Any input would be greatly appreciated. Let me know anything you know about this system. So many people have torn apart all of this for CarPlay mods and other reasons that surely someone will know something about this usb cable connection. I will expand my search to other Porsche models as well because even if the port location differs by model I bet the cable and stuff is the same. I did not find anything useful on initial search though. I will try to update as I work through this problem during my free time.

Thanks for reading all that

tl;dr
Usb port not working with any devices. Does anyone know anything about replacing the cable or port? Any recommendations to look into prior to doing that?

dollarlongnecks

It's possible the previous owner did something to that outlet. Those USB ports are easy to break if you bend or twist something too much.

Also, when I added the CarPlay into the PCM on my Cayenne, I rewired that port to connect to the CarPlay box instead of the PCM, so I guess it's possible it's been messed with.

Think the part is pretty inexpensive (relatively for Porsche) so it might be worthwhile to order one, then take everything apart and see if you can see any issues, and if not, do the replacement and see if that fixes the problem. I think you might be able to get into that area without taking apart the entire center console, but do some reading in the DIY area to be sure.

Neopolymath

I think this is the most efficient plan. Thanks

Neopolymath

Update: USB multimeter used with phone and flash drive plugged in. No amperage being measured. Voltage is around 3.5-3.7v. Clearly, this isn't correct function and indicates an open circuit if I'm remembering my physics right. Maybe a ground contact is broken? The caveat is that I did this in accessory mode not with the car running. Will meet with friend to measure his voltage and amperage as well as swap in his usb port from his CTT. If his known good port works in my vehicle then I will know it's the port not the cable and proceed with simply R&R of the port instead of further testing. Obviously, this part is cheap enough to just buy before confirming but it will take a few days to get here so I will just go ahead with testing for fun

For future searchers, if you have PCM 3.1 then the part number is 95864235100 for the port. Don't accidentally purchase the faceplate that's like $6 instead. (Disclaimer: Always verify part numbers you read on the internet...)

simon81

Hi @Neopolymath, I was wondering if you had updates on this issue and whether the port replacement did the trick?

I just bought a 958.2 Cayenne GTS with the same issue and was doing some research.

thanks
Simon