USB Device Not Available: Troubleshooting Guide

I have a USB port installed in my Caddy from the factory, and I've connected a USB stick containing my music to it. I can access the stick through my radio, allowing me to select different folders and listen to the music through the radio.

Since I own an iPhone, and the battery on this amazing phone tends to run out quickly if you use it a lot, I thought I would charge it using the USB port with my original charger.
Done. I plugged the charger into the USB port, connected the phone, and what happened? --> "Device not available."

I figured I wouldn't be able to access the music on the iPhone, but I didn't expect that I wouldn't even be able to download it .

Is there a way to code something here that supports the charging function, or even makes it recognized as an iPod, so that it charges and you can even access the music?

Hi,

Perhaps the device is drawing too much power. It's limited by the USB specification, but many devices/external hard drives still work because modern PC motherboards are designed to handle that.

I am not aware that the USB port can be reconfigured in this way. Why would VAG (Volkswagen Group) make such a feature selectable in the radio?

There might be charging adapters with a USB connection available for the cigarette lighter socket.

Best regards, Rainer.

Rainer K. wrote:

Hi, Perhaps the device is drawing too much power. It's limited by the USB specification, but many devices/external hard drives still work because modern PC motherboards are designed to handle that. I am not aware that the USB port can be reconfigured in this way. Why would VAG (Volkswagen Group) make such a feature selectable in the radio? There might be charging adapters with a USB connection available for the cigarette lighter socket. Best regards, Rainer

For the cigarette lighter, I have a plug from Hama. You plug that in, plug in the USB charging cable, connect the iPhone, and the iThing } will charge.

Perhaps we could recode something there.
I could have ordered the device with an iPod interface, which would have made it work, but then I wouldn't have been able to order my beloved height-adjustable center console.

I wouldn't be surprised if it were intentional (and involved additional development effort) that it doesn't work without the iPod add-on...

"As long as the iDings doesn't draw too much power, something like that should work. Otherwise, it's not a USB port. Did you order and pay for a USB port, or just a connection for USB mass storage devices?"

I ordered and paid for the USB port from Volkswagen at the factory.

Jochen912 wrote:

I ordered and paid for the USB port from VW at the factory.

Then check if the device meets the USB specification during charging, and if everything is okay, file a complaint.

Wikipedia wrote:

In the year 2000, USB 2.0 was specified, which primarily added a data rate of 480 Mbit/s, enabling the connection of hard drives or video devices. However, products for this only appeared on the market starting in 2002. It should be noted that each port must guarantee a maximum of 500 mA (High Power) or 100 mA (Low Power) as power supply. This value is generally not sufficient for 3.5" hard drives, which is why an external power supply is required. For 2.5" hard drives, which require 500 mA for continuous operation, various solutions are used to cover the higher inrush current. In addition to an external power supply, a capacitor is sometimes used as a temporary energy storage device, or a second USB port is used (which is not standard-compliant in this form). 1.8" hard drives also have enough power from a single port to start up. In 2008, the new specifications for USB 3.0 SuperSpeed were introduced, achieving data transfer rates of at least 4.8 Gbit/s. This specification also introduces new connectors, cables, and sockets, which are mostly intended to be compatible with the old ones. [2] With USB 3.0, the power supply is also increased to 900 mA, which ensures the power supply for 2.5" hard drives.

I just checked the iPhone charger, where the USB cable plugs in, and it says:

Input: 100 - 240V - 0.15A (0.15A) 50 - 60 Hz Output: 5V 1A

and the Hama cigarette USB drive has the following specifications:

12V to 5V/700mA.

And with this, I can charge my iPhone in the car.

If I charge the iPhone using the original USB charging cable connected to the computer, it does charge, so the USB specifications should be correct, right?

I thought that VW might have intentionally disabled the USB port from the factory for iPods and iPhones, so that customers would have to order the iPod integration system as an add-on.
What I would have also done, if I had been able to order the adjustable center console at the same time.

That's exactly what it's called, and that's how I ordered it from the factory.

MEDIA-IN multimedia port (USB) for connecting external storage devices, operated via the radio or radio navigation system.

As I mentioned, I plug in my USB stick with music to play it.

And even charging the phone is not possible.

Quote:

MEDIA-IN multimedia port (USB) for connecting external storage devices

.
Okay, so everything is clear, since it doesn't explicitly state that phone charging must be available. I still find it a shame. USB hard drives with music on them probably won't work either, due to the high inrush current they require.

Well, maybe there will be a chance someday to modify the USB port so that you can at least charge something with it .

Does the i also charge with any non-Apple USB cable on a PC? My Becker navigation system, for example, does not.

Hi,

Okay, so it's like this: I plug the USB cable into the laptop, and on the other end, there's a special connector that goes into the iPhone. It's only compatible with the iPhone and the iPod.

But regarding your Becker navigation system, I also have one, and I've already loaded it onto my laptop.

Hello,

It's likely that your USB port will only fully activate the power supply once a compatible device (device class) is detected.

The USB standard stipulates that devices must initially register with the bus in a low-power (100 mA) mode and only switch to the high-power (500 mA) mode with the host's permission.

A phone that needs to be charged requires the Hi-Power mode. However, since the phone is not a valid device class for this port (the connection for storage media!), it will not activate the Hi-Power mode (the device in the car doesn't have a driver for an iPhone...). Therefore, I don't think there's a fault with the device itself...

I'm familiar with this from older Motorola phones. They always used mini-USB for charging. However, it only worked after the computer had also installed a driver for the phone. Exception: a cheap, externally powered USB hub.

Best regards from an IT professional.
winschrott

Oh yes, before I forget:

One possibility would be to disconnect or insulate the D+ and D- data lines of the USB cable. In a standard connector, these are the middle pins. The device could then draw the 500mA directly from the line, regardless of the standard. I don't know if this works with an iPhone, and it's also possible that a poorly designed port could be damaged if the device draws more current than the port is specified for, and there is no (thermal) fuse installed.

I wouldn't hesitate to use such a port with an external drive, although I can't guarantee it will work. It's not excluded or prohibited to connect an external drive. However, 2.5' drives typically require more than 1A of power to start up. This port should either be able to handle that power draw, or it should trip the fuse.

VG