E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 39 votes, 5.00 average. Display Modes
Old 01-10-2011, 01:14 AM   #1
mrhappyface
Registered User
 
Join Date: Dec 2010
Location: so ca
Posts: 11
My Ride: e46 325ci
need help id key fob component

OK i sliced opened my BMW fob and in the process i whacked off a component (part) off the circuit board and didn't notice it at first so who knows where it is now i just need a clear picture of one and hope i can id it mainly just need to know if it is a diode or a capacitor .I already ordered a new key from the dealer but still would like to get this one working again .My battery terminal was loose and i already repaired that so that's the reason for opening up in the first place see attached pic for component location
Attached Thumbnails
Click image for larger version

Name:	bmwkey.JPG
Views:	2101
Size:	61.8 KB
ID:	389281  
mrhappyface is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 01-10-2011, 11:26 AM   #2
scottjoh
Modded ///Member
 
Join Date: Aug 2008
Location: Torrance, CA
Posts: 2,624
My Ride: '99 323i & '02 540i
Here's a picture
The part is a capacitor, but, there are no markings on the part. It's a 0603 package and judging by the location and what it's hooked up to it's somewhere between 4 and 15 pF. I'll try and measure it the next time I get a diamond key for in for repair. If you want you can send it my way and I'll try a bunch of values in the range and test it.

scottjoh is offline   Reply With Quote
Old 01-10-2011, 07:15 PM   #3
mrhappyface
Registered User
 
Join Date: Dec 2010
Location: so ca
Posts: 11
My Ride: e46 325ci
awesome thanks for the pic ill let you know but im pretty confident i can get it working now that i know what the part is now but i let you know just in case
mrhappyface is offline   Reply With Quote
Old 05-01-2011, 06:48 PM   #4
bakler
Registered User
 
Join Date: May 2011
Location: Delaware
Posts: 2
My Ride: 2003 330i
Killed the Key Fob. It was dying. And, I did it in.

Hello Gentlemen. I finally registered. But, I've visited freqently. I'm old, but new and hoping someone can help.
So,...I essentially did the same thing MRhappyface did, (looking at his pic)on the same side of the board, but to the right,...four components excised. Does anyone have a schematic?,...or know where to find one?

I looked at it with my loupe. And, I can identify a number on the larger, damaged component, but nothing for anything else (because they're missing).

So, thanks in advance if anyone can help.
bakler is offline   Reply With Quote
Old 05-01-2011, 07:51 PM   #5
Hammer432
Registered User
 
Join Date: Sep 2010
Location: Maryland USA
Posts: 297
My Ride: 2001 330i 3 pedals
I have never seen a schematic for the key. If you are proficient at soldering small components your best bet may be to buy a used key from eBay and use parts from that to repair your key. They keys go for about $30. Or you could just sent it to Scottjoh for repair as he seems to be the resident expert here.

Last edited by Hammer432; 05-01-2011 at 07:54 PM.
Hammer432 is offline   Reply With Quote
Old 05-01-2011, 08:38 PM   #6
bakler
Registered User
 
Join Date: May 2011
Location: Delaware
Posts: 2
My Ride: 2003 330i
Thank you, Hammer432. Tomorrow, I'll pursue it with Scottjoh.
bakler is offline   Reply With Quote
Old 04-08-2013, 07:13 PM   #7
TonyJ
Registered User
 
Join Date: Nov 2011
Location: Melbourne, Australia
Posts: 331
My Ride: E46 330i
Quote:
Originally Posted by scottjoh View Post
Here's a picture
The part is a capacitor, but, there are no markings on the part. It's a 0603 package and judging by the location and what it's hooked up to it's somewhere between 4 and 15 pF. I'll try and measure it the next time I get a diamond key for in for repair. If you want you can send it my way and I'll try a bunch of values in the range and test it.

Oh dear. I made the same mistake like the OP! I was very cautious and made hundreds of light cuts but the case won't open. Was eventually frastrated and impatient and now I wracked the same capacitor. To make things worse, the blade cut it in half!

I can buy 100 0603 caps from ebay for peanuts but not sure of the value. Have you had a chance to measure it?

Last edited by TonyJ; 04-08-2013 at 07:14 PM.
TonyJ is offline   Reply With Quote
Old 04-09-2013, 05:39 AM   #8
TonyJ
Registered User
 
Join Date: Nov 2011
Location: Melbourne, Australia
Posts: 331
My Ride: E46 330i
Haha, I fixed it!

I actually wracked two components. One is the 150 ohm resistor, the other is the unknown value capacitor. The resistor was in good shape, so soldered right back and tested resistance on board was good. The capacitor was cut to half. So I just soldered both ends on and let them touch. (I'm too unprofessional of course)
Click image for larger version

Name:	P1080485.jpg
Views:	1340
Size:	51.2 KB
ID:	499601
I secretly hoped that a) this cap is in parallel to the resistor, so it might just provides some noise suppression and will probably still work without it; b) it is only several pF so even if they are not electronically connected there will still be some small capacitance between them.

And I was right. After reprogram the key, it worked straight away.

However I'm still puzzled why it wasn't working before which prompted me to open it. The battery was 2.98V so not a battery problem.

The BMW key is a bit of a myth. Half a year ago it stopped working after one week of not using. But after charging and reprogramming it worked fine until yesterday when it just suddenly stopped working. No matter how many times of reprogramming it just always dead. The key is used (and charged) everyday BTW.

The battery may still need to be replaced in the future but I won't super glue it for now.
TonyJ is offline   Reply With Quote
Old 04-09-2013, 08:16 PM   #9
scottjoh
Modded ///Member
 
Join Date: Aug 2008
Location: Torrance, CA
Posts: 2,624
My Ride: '99 323i & '02 540i
TonyJ,
Wow, I'm surprised it worked. I suspect it will probably fail again since the root cause of your problems is most likely not those two components. If you get a chance measure the voltage on the battery. I bet it's 3.2-3.3 Volts which is near fully charged. The transmitter will start dropping out when the voltage gets below about 2.0 Volts under load which is when the undervoltage lockout circuit kicks in.

Last edited by scottjoh; 09-18-2013 at 10:32 AM.
scottjoh is offline   Reply With Quote
Old 04-23-2014, 09:53 AM   #10
omodos
Registered User
 
Join Date: Nov 2011
Location: cyprus
Posts: 127
My Ride: 318 auto n42
Quote:
Originally Posted by scottjoh View Post
TonyJ,
Wow, I'm surprised it worked. I suspect it will probably fail again since the root cause of your problems is most likely not those two components. If you get a chance measure the voltage on the battery. I bet it's 3.2-3.3 Volts which is near fully charged. The transmitter will start dropping out when the voltage gets below about 2.0 Volts under load which is when the undervoltage lockout circuit kicks in.
Sorry to be hijacking this post, but i did something crazy last night, had the 'known' issue whereby the key would simply spin in the lock on the drivers door and not lock or unlock central locking (luckily car was unlocked) in my wisdom i picked up key that was working and started messing about trying to programme an already working key, it stopped working! in the meantime the spare key stopped too, eventually the ignition switch trick 5 times and then hold unlock down whilst pressing lock button 3 times fixed the working key again so now i can lock unliock with this! now my spare was dead and the lock button was a problem before all this as I could not hear a little click when pressing down---so i couldnt reprogram this key becos of this issue, cut a long stroy short, i cut key open re-inserted the contact under the lock button on the fob BUT sliced away 6 capacitors, 2 are cream in colour any number...PLEASE is there anyone out there who knows where the capacitors or diodes go? so i can try resolder on? attached are pics in red boxes are the capacitors that are missing
Attached Thumbnails
Click image for larger version

Name:	IMG_4151 damage2.jpg
Views:	523
Size:	63.7 KB
ID:	555157   Click image for larger version

Name:	IMG_4152capacitors.jpg
Views:	336
Size:	114.6 KB
ID:	555158  
omodos is offline   Reply With Quote
Old 04-23-2014, 12:33 PM   #11
scottjoh
Modded ///Member
 
Join Date: Aug 2008
Location: Torrance, CA
Posts: 2,624
My Ride: '99 323i & '02 540i
Quote:
Originally Posted by omodos View Post
Sorry to be hijacking this post, but i did something crazy last night, had the 'known' issue whereby the key would simply spin in the lock on the drivers door and not lock or unlock central locking (luckily car was unlocked) in my wisdom i picked up key that was working and started messing about trying to programme an already working key, it stopped working! in the meantime the spare key stopped too, eventually the ignition switch trick 5 times and then hold unlock down whilst pressing lock button 3 times fixed the working key again so now i can lock unliock with this! now my spare was dead and the lock button was a problem before all this as I could not hear a little click when pressing down---so i couldnt reprogram this key becos of this issue, cut a long stroy short, i cut key open re-inserted the contact under the lock button on the fob BUT sliced away 6 capacitors, 2 are cream in colour any number...PLEASE is there anyone out there who knows where the capacitors or diodes go? so i can try resolder on? attached are pics in red boxes are the capacitors that are missing
The components are completely ruined. Usually when they are hacked off, like you did, the metal connection on the end is damaged and no longer make connection to all the layers in the ceramic thus reducing it's capacitance. I always replace any component that is damaged. There is one more component that need to be replaced. Just to the right of the upper left red square is a capacitor that is crooked and most likely damaged like the rest. Since 5 of the 7 damaged components are in the RF section there is no easy answer to the component values. They are tuned for the board and the components used. A 4.7pf capacitor from one manufacturer in many cases is not the same as a 4.7pf from another manufacturer when used in an RF application. Someone in another thread posted the value ranges for many of the components that you need to replace.
scottjoh is offline   Reply With Quote
Old 04-26-2014, 04:30 AM   #12
omodos
Registered User
 
Join Date: Nov 2011
Location: cyprus
Posts: 127
My Ride: 318 auto n42
scottjoh thanks for the reply so I need a new key really, BUT am going to risk try soldering the components back on , in your experience and if you can be kind enough to let me know the components marked 432 and 151 i have outlined in red, do they have any polarity as such?are the diodes? would it matter what whay round they are soldered on ?reason i ask is i have scanned the web for hours and have found differing pics, in this pic as you look at it the items in red marked 432 one is 'upside down ' as such, whereas in other pics i have see the numbers as you look at them are inline 432 432, same goes for the 151, if that sense?
Attached Thumbnails
Click image for larger version

Name:	diamond_key_zoom.jpg
Views:	467
Size:	34.4 KB
ID:	555598  
omodos is offline   Reply With Quote
Old 04-26-2014, 11:42 AM   #13
scottjoh
Modded ///Member
 
Join Date: Aug 2008
Location: Torrance, CA
Posts: 2,624
My Ride: '99 323i & '02 540i
need help id key fob component

Orientation of the components marked 432 and 151 do not matter.

I do key repair in case you need it. Here are some of the keys I've repaired www.bmwgm5.com/kf_wos.htm



Sent from BimmerApp mobile app

Last edited by scottjoh; 04-26-2014 at 12:30 PM.
scottjoh is offline   Reply With Quote
Old 04-27-2014, 04:42 AM   #14
omodos
Registered User
 
Join Date: Nov 2011
Location: cyprus
Posts: 127
My Ride: 318 auto n42
scottjoh again thanks for the reply, please feel free quote a price here or via private mail on the cost of repair ( 6 sliced off components as in a pic i included somewhere in this post) and if you can be so kind enough the cost of shipping back to Cyprus once repaired.....? key is nearly totally useless but it still starts the car at least....all started cos the door lock mechanism would move freely and not lock or unlock car, in my wisdom try reset keys but of course the lock button was faulty on one so I sliced it open, repaired the lock button but in the process destroyed 6 parts....hmmmmm
omodos is offline   Reply With Quote
Old 04-24-2017, 12:34 PM   #15
jeffbert
Registered User
 
Join Date: Apr 2017
Location: Seattle
Posts: 19
My Ride: 03 325Ci Convertible
Revisiting old post Did anyone determine the Capactitor value for this one?

I also lost mine when replacing the battery. The battery was a goner as the metal bracket that holds it to the PCBA had broken. I sadly broke off the same capacitor un-knowingly when opening up the key fob.

Hoping to get the correct value in pF. Anyone? Is 4.7pF Correct?

Last edited by jeffbert; 04-24-2017 at 12:35 PM.
jeffbert is offline   Reply With Quote
Old 04-28-2017, 04:29 PM   #16
jeffbert
Registered User
 
Join Date: Apr 2017
Location: Seattle
Posts: 19
My Ride: 03 325Ci Convertible
As a followup... I got mine fixed by putting a 12pF capacitor (0805 size LOL, 0603 is correct but I didn't have one laying around and all I had laying around was a 12pF 0805) in this spot. Works great. US Version.
jeffbert is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 02:38 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use