Bimmerfest - BMW Forums - View Single Post - Z4 Roadster (E85) E85 Z4 3.0si bluetooth pairing button DIY

goeslikeschnell · #1 10-07-2012, 11:34 AM

This is a DIY on how to make your own pairing button for a BMW bluetooth module. This is specific to the E85 Z4, but should work for other models with slight changes for which wire to connect to. There is a plethora of information about E46 models and this borrows from that.

The gist is that you need to connect pin 1 and GND on the 18 pin connector.

Install instructions for the ULF module can be found here: http://www.bimmernav.com/BMW_Z4_Blue...tructions.html

Since BMW discontinued the E46 bluetooth pairing button you now have to DIY it yourself, or spend $170 on their button. DIY it is!

The connection is located behind the passenger seat speaker grill. You can see that it's mounted, give it about a half turn clockwise and it should come loose.

Click image for larger version

Name: IMG_0109 copy.jpg
Views: 44
Size: 149.0 KB
ID: 344672

Click image for larger version

Name: IMG_0120 copy.jpg
Views: 42
Size: 145.0 KB
ID: 344673

I bought a push button from Radioshack for about $3 in black to match with my interior. It seems that they only had bright red or black. I then soldered some speaker wire to the two connections and wrapped with tape.

The button required a 1/2 inch hole. Here it is mounted behind the passenger seat.

Click image for larger version

Name: IMG_0123 copy.jpg
Views: 35
Size: 128.3 KB
ID: 344674

Click image for larger version

Name: IMG_0125 copy.jpg
Views: 28
Size: 158.8 KB
ID: 344675

Next task is to find the activation wire for the bluetooth in the connection. You will have to pull off the outer cover to get to the wires. Based on the research it seems that the cable is pin 32 on the ULF connector but is a different color in the cars cabin. Here it's Yellow & Red. This is the wire removed from the connector. In the E85 it was pin 1 and GND. The easiest way to find it is to connect a wire to GND and then turn the key to position 1. Then touch each wire until you here bluetooth activate. The one that activated the system is the wire you need.

Click image for larger version

Name: IMG_0127 copy.jpg
Views: 28
Size: 179.5 KB
ID: 344676

Click image for larger version

Name: IMG_0128 copy.jpg
Views: 35
Size: 192.9 KB
ID: 344677

Here we are soldering pin 1 to one wire from the button.

Click image for larger version

Name: IMG_0130 copy.jpg
Views: 30
Size: 146.3 KB
ID: 344679

Click image for larger version

Name: IMG_0129 copy.jpg
Views: 31
Size: 138.7 KB
ID: 344678

Complete, just need to wrap with electrical tape.

Click image for larger version

Name: IMG_0133 copy.jpg
Views: 28
Size: 154.4 KB
ID: 344680

The other wire from the button we connected and soldered a connector to attach under a screw for GND.

Click image for larger version

Name: IMG_0134 copy.jpg
Views: 23
Size: 119.6 KB
ID: 344681

Click image for larger version

Name: IMG_0135 copy.jpg
Views: 21
Size: 108.4 KB
ID: 344682

Then loosen a screw and tighten the GND connector under it.

Click image for larger version

Name: IMG_0136 copy.jpg
Views: 28
Size: 160.9 KB
ID: 344683

And that's it! You now have a pairing button for about $5 and an hour of work.