BMW Y Cable - iPhone says "Error" when switching to USB?

[cyrax83]

Hi,

I have a 2010 E82 with the BMW Professional (CD73) stereo head unit. There is no I-Drive or Sat Nav. The car is also fitted with an AUX and USB Port in the center console. I also have Bluetooth so I can receive phone calls over the system.

I want to connect my iPhone 5S so I can use steering wheel controls and headunit integration. I bought a BMW Y cable (USB/AUX on one end and Lightning on the other) and when I connect it then try to switch to "USB" - the headunit says "Error" when I try select USB. When I try switch over inputs with the steering wheel control, it says "Unsupported Dev". The iPhone does charge but can't select it on the headunit except for AUX.

The options I have the Audio menu on my headunit are Tuner, CD, USB and AUX

- AUX works fine including using the Y cable from my iPhone. The iPhone also charges but can't control the songs from the headunit or steering wheel
- Other USB devices work fine including my USB thumb stick which has full headunit/steering wheel integration
- Can't seem to get my headunit to recognise my iPhone

I also tried my iPad Air and same deal. This was the Y cable that I bought (although I don't think it's the Y cable) - http://www.ebay.com.au/itm/111243714...84.m1439.l2649

I entered my VIN at bmwvin.com and it does say I have S6FLA USB-AUDIO-SCHNITTSTELLE USB/Audio interface - if that helps

I also tried a standard Apple USB to lightning cable for shits and giggles as a test obviously that did not work

Any ideas on what to do?

[halfhalo]

I have never heard of a lightning to y cable ever working identically to the 30-pin cable, with the biggest reason being that the lightning connector does not natively support the Ipod serial protocol that the car is expecting.

A Lightning to 30pin + 30pin cable works fine, however, since the adapter itself converts the commands and also incorporates a DAC for line out. It handles my iPhone 5 and iPad Mini just fine, keeping in mind the 500ma limit of the car's usb port.

[cyrax83]

Thanks, so I need to buy a Y cable to 30 pin, then a generic 30 pin to lightning adapter? That is bizarre...

Anyway I've bought these two - hope they work

1. MD824ZM/A 30 pin to Lightning Adapter genuine
http://www.ebay.com.au/itm/121301503...84.m1497.l2649

2. BMW Y Cable 30 Pin
http://www.ebay.com.au/itm/110950203...84.m1497.l2649

will report back

[cyrax83]

It worked, although sound quality is pretty lame

[halfhalo]

If SQ is suffering, I would bet that either the cable or the 30pin adapter is not functioning properly.

When one of the cheapo 30pin y cables I bought started to die, they had a habit of sounding way off, like the 3.5mm cable was not fully seated in the jack, along with the annoying habit of dropping the serial connection temporarily, which caused the stereo to become unresponsive to any commands that were to be sent to the iphone (IE changing songs) until the stereo dropped back into fm mode since it no longer thought the iphone was there.

Also, my previous statement of BMW not having a lightning Y cable is now wrong. They apparently came out with one recently with the P/N of 61122287642. I have not tried it since I'm going to assume the DAC in the 30pin adapters are of a higher quality than whatever DAC is in the y-cable.

[Harlequin]

Genuine Y-Cable is pricey but WAY better in both SQ and reliability than the eBay jobbies.

Sound through the Y-Cable is actually using the headphone jack to output audio rather than digital output through the 30 pin connector so SQ will never be as good as it could be...

[cyrax83]

Originally Posted by Harlequin

Genuine Y-Cable is pricey but WAY better in both SQ and reliability than the eBay jobbies.

Sound through the Y-Cable is actually using the headphone jack to output audio rather than digital output through the 30 pin connector so SQ will never be as good as it could be...

Yep I noticed this when I unplugged the USB and the sound kept playing. Very silly. I have read that sound suffers because the USB does not provide enough power to the phone amp, which is why playing off a USB stick sounds good?

I've read buying part 61 12 2 167 663 improves sound by giving more power to the phone

[Harlequin]

Originally Posted by cyrax83

Yep I noticed this when I unplugged the USB and the sound kept playing. Very silly. I have read that sound suffers because the USB does not provide enough power to the phone amp, which is why playing off a USB stick sounds good?

I've read buying part 61 12 2 167 663 improves sound by giving more power to the phone

It's more that the iPhone is outputting an analog headphone-level audio stream via the 3.5mm jack and then the little black box in the Y-cable is converting it back to line-level audio.

I think the genuine BMW one has a better quality Line Level Converter in it. (just guessing though)

It's never going to be as good digital output from the 30-pin/lightning socket but it's worth spending the extra to get a genuine Y-Cable...

[halfhalo]

Originally Posted by cyrax83

Yep I noticed this when I unplugged the USB and the sound kept playing. Very silly. I have read that sound suffers because the USB does not provide enough power to the phone amp, which is why playing off a USB stick sounds good?

I've read buying part 61 12 2 167 663 improves sound by giving more power to the phone

I actually have that part, but don't use it. Instead, I have a little 30pin power injector that pulls power from a usb charger and injects it between the y-cable and the lightning adapter. Slightly more finnicky due to the power outlet shutting down while the usb port staying power up, but it actually does provide enough juice to charge the phone while gps, bt, and the screen are all active.

Plus, that W cable only works when the ignition is on, since it requires the power outlet to be on to work.

As for the W having better sound quality, it shouldn't make a difference. The phone is powering the lightning adapters audio chip. Whether the phone is charging or not has nothing to do with that.

Originally Posted by Harlequin

It's more that the iPhone is outputting an analog headphone-level audio stream via the 3.5mm jack and then the little black box in the Y-cable is converting it back to line-level audio.

I think the genuine BMW one has a better quality Line Level Converter in it. (just guessing though)

It's never going to be as good digital output from the 30-pin/lightning socket but it's worth spending the extra to get a genuine Y-Cable...

The Y cable is not getting audio from the headphone jack, but from the phones (or in this case the lighting adapters) Line Out. Still analog, but it is indeed a Line Out. The little black box is passing that straight through to the car, which is why it still plays when the usb is unplugged.

The usb side is different. I don't recall if there is a microprocessor in it or just a board, but what it is doing is essentially converting the iPod Accessory Protocol with a 30pin adapter to whatever the car expects (Which if I had to guess was still the Accessory Protocol) on the USB side.

This is also why the lightning adapters are as expensive as they are. While the 30pin connecter physically has pins for LOC, the lightning doesn't. Instead a micro controller gets data over the lightning bus, and then sends the appropriate data out on the individual 30pin pins and vice versa. For audio, it has a dsp chip in it as well.


With all that said, CD's/USB drives will indeed have better sound than iPod in, since the iPod in does have that analog component. Now, whether you will actually notice the difference is another thing entirely. Can I tell the difference if I listen to one after the other? Yes. But its a small enough difference for me to not care 99% of the time (although I do have both a CD and usb drive in the car for those rare cases).

[cyrax83]

Originally Posted by halfhalo

I actually have that part, but don't use it. Instead, I have a little 30pin power injector that pulls power from a usb charger and injects it between the y-cable and the lightning adapter. Slightly more finnicky due to the power outlet shutting down while the usb port staying power up, but it actually does provide enough juice to charge the phone while gps, bt, and the screen are all active.

Can you link me to something like this?

cheers

[halfhalo]

I use the dockStubz+ from here: http://www.cablejive.com/products/dockStubz.html

The lightning dockStubz doesn't inject power, and neither does the normal dockStubz. Only the dockStubz+ has a micro-usb port for power.

[Harlequin]

Originally Posted by halfhalo

The Y cable is not getting audio from the headphone jack, but from the phones (or in this case the lighting adapters) Line Out. Still analog, but it is indeed a Line Out. The little black box is passing that straight through to the car, which is why it still plays when the usb is unplugged.

Sorry. I meant that it's using the CAR's 3.5mm Headphone jack... not the iPhone's... My bad...