Looking for front window relays for your BMW GM3, GM4 or
GM5 module?
These relays are P/N: V23078-C1002-A303 and made by Siemens
Price is $16 each including shipping within the US and $20
each including shipping to anywhere outside the US.

These are the relays used to control the front windows in
cars that use the GM4 (ZKE4, GMIV), GM5
(ZKE 5) module. These cars include the E46 (3-series), E85 (Z4), E83 (X3)
and E52 (Z8). It is also used in the GM3 (ZKE III)
module to control the rear windows and rear door locks. The GM3 is used in
the E38 (7-series), the E39 (5-series) and the E52 (X5). It is also used in
the Relay Module 4 (RMIV) on E36 3-series.
What's this E-number business? Not sure what your car is? Check
out the excellent BMW timeline at the bottom of this page on Wikipedia. http://en.wikipedia.org/wiki/BMW_E85
Every GM5 module that I've worked on or seen has used this relay for the front windows. It doesn't seem to matter if the car is for the US, UK, etc, markets.
The GM5 is located behind the glove box in a white plastic module holder. Someone on the net made a really good "How To" on removing the GM5 from the car. You can download it here, GM5 Removal Procedure. I don't know who the author is, but, I want to give him credit for taking the time to create this How To. I created my own how to remove the GM5 module which you can find here My GM5 Removal Procedure.
Which relay controls what windows. Being the curious person I am, while my GM5 was going in and out of my car for testing of the door lock issue I decided to figure out what the other relays did. I wired up little LEDs in parallel with the relay coils and started rolling my windows up and down. These relays are doubles so each relay has two functions. See the picture below. The large relays are for the front windows and the smaller relays are for the rear windows. BTW the smaller relays, V23084-C2001-A303 are the same as those used on the door locks, so if you need a pair of those click on the part number and it will take you to my information page. On 2 door coupes these relays are sometimes not installed.

Relay Diagram

What to do next?
If you want to send in your GM5 for repair let me
know. Contact me via email at scott@bmwgm5.com or call me at work. My number
is 310-283-4273 to check my schedule and arrange the repair. Payment should
be made in advance via PayPal to account scott@bmwgm5.com or by money order
shipped with the module. When you email or call I will give you the address
to ship it to and let you know my schedule so that your module doesn't sit
around while I'm on a business trip or on vacation or something.
If you don't feel comfortable sending a stranger money and your module you can deal with me in the eBay arena. I keep an auction going for a pair of relays. You can find me by searching for my User ID: BMWGM5. I am a Top-rated seller with over 540 feedback and 99.6% positive. This way if you are unhappy you have a forum to let others know of your experience and petition to get your money back if I disapear. Going through eBay does cost a bit more though. On eBay they are $11.99 plus $6 shipping and buying direct they are $16 including shipping within the US. $20 each including shipping to anywhere outside the US. The higher cost on eBay is to offset the ever increasing eBay fees!
What's the turn around time?
I you paid for Express Mail next day return shipping
I try my best to ship the modules back the same day I receive them. So, if
you ship it to me next day air I will do the repair within hours of receiving
it and get it to the post office before the 4pm Express Mail deadline. In
this case door to door turn around time is about 48 hours. If you paid for
Priority Mail return shipping, I will repair it and ship it back within 24
hours. All repairs will be done at an antistatic workstation by a competant
tech. Unfortunately I won't be able to test it out after the repair, but,
I will clean it and carefully inspect it under a microscope to verify that
it was done correctly.
I want to
do it myself and just need the relays.
I will sell them to you, but, I don't recommend doing
this job yourself unless you are a competant solderer. The relays are very
hard to get out due to the large copper area on the component side of the
board and the use of lead free solder which has a higher melting point than
the old tin-lead solder. Forget about trying to use solder wick. This is not
an easy job and you risk damaging the board, plated through holes and having
to replace the entire module at significant expense. With that said, the cost
of the relay is $16 each including shipping within the US and $20 each including
shipping to anywhere outside the US. Payment via PayPal
is prefered. My account is scott@bmwgm5.com. Again you can go through my eBay
auction if you don't feel comfortable dealing with me directly. My User ID
is SCOTTJOH. I have more than 3550 feedback and 100% positive feedback.
Other Options:
Don't want to get your GM5 module repaired? You could go to the dealer and
buy a new one. They're about $550-$700 plus $120/hour for labor. There is
also Bavarian Auto Recycling,
they have used GM5 modules for sale for 52-85% off the current BMW list price,
but, remember these are pulls from cars being parted out. You have no idea
how much life is left in these relays and they may fail at any time. Plus
the dealer will have to program it to correctly work in your car.
Got a comment? Want your GM5 module repaired? Just want a pair of relays? Send me an email or give me a call. My email address is scott@bmwgm5.com and my phone number is 310-283-4273.
Other relays I sell
V23072-C1061-A303
V23072-C1061-A309
V23084-C2001-A303
V23086-C1001-A403
V23086-C2001-A303
V23133-C133-A1001