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 Rate Thread Display Modes
Old 01-11-2013, 09:03 AM   #21
dmitrofed
Registered User
 
Join Date: Jan 2011
Location: Ohio
Posts: 137
My Ride: Red 2001 330xi
That test won't really be valid because you're just checking the integrity of the sensor which should be fine, you need to actually see if they are reading the wheel speed or not, that's why you need the scan tool
__________________
dmitrofed is offline   Reply With Quote
Old 01-11-2013, 10:58 AM   #22
Pig_Pen
Registered User
 
Join Date: Feb 2012
Location: mn
Posts: 24
My Ride: 325xi
If the voltage is changing, it is due to the sensor reacting to the tone ring, no? I can see a resistance check only validating the sensor.

From other thread:
To the OP. Jack and remove the wheels. Disconnect the wheel speed sensor(s) from the harness in the wheel well. You'll need a digital volt meter (DVM). Connect the meter leads to the wheel speed sensor - polarity doesn't matter. Select the milivolt range (mV). Spin the hub and observe the meter. You should read between 1 and 5 mV when you spin the hub. No output = a defective and/or dirty sensor. Cheap and effective. Good luck.
Pig_Pen is offline   Reply With Quote
Old 01-13-2013, 11:43 PM   #23
dmitrofed
Registered User
 
Join Date: Jan 2011
Location: Ohio
Posts: 137
My Ride: Red 2001 330xi
it should change theoretically but idk if you'll even notice much spinning by hand anyways since you have an axle that'll make it hard to spin fast
__________________
dmitrofed is offline   Reply With Quote
Old 01-14-2013, 02:22 PM   #24
Pig_Pen
Registered User
 
Join Date: Feb 2012
Location: mn
Posts: 24
My Ride: 325xi
here is a vid that shows resistance changing -
Pig_Pen is offline   Reply With Quote
Old 01-14-2013, 02:41 PM   #25
RayPooley
Registered User
 
Join Date: Jul 2012
Location: Liverpool
Posts: 1,460
My Ride: 320i SE Coupe
A speed sensor is just a permanent magnet with a copper coil around it. Any magnetic object that moves through the flux surrounding the magnet alters the flux density surrounding the copper coil and induces an electo motive force (a voltage) in the copper coil. This can be detected using a multimeter as either voltage of current. There are three things that can affect the performance of the sensor as far as these applications are concerned.

The gap between the sensor and the rotating element. Any crud bridging this gap will affect the flux density and, in turn, the induced voltage. Reduced voltage may be interpreted as fault by DME.

The condition of the copper coil. Most unlikely to fail but if it did then no signal would be detected by DME.

The strength of the flux of the permanent magnet. Magnets fade over time especially in hot environments. This will affect the flux density and, in turn, the induced voltage. Reduced voltage may be interpreted as fault by DME.

So clean and measure voltage to ensure that it is within acceptable range.

If all is ok then suspect problem elsewhere. Connections to DME for example.

Last edited by RayPooley; 01-15-2013 at 03:39 AM.
RayPooley is offline   Reply With Quote
Old 01-14-2013, 08:28 PM   #26
dmitrofed
Registered User
 
Join Date: Jan 2011
Location: Ohio
Posts: 137
My Ride: Red 2001 330xi
dude its no coincidence that it happened right after you did bearings, stop being cheap and doing pointless stupid stuff and just go to a shop and have them tell you which wheel isn't reading, don't have them DIAGNOSE it just ask them how much it'll cost you for them to tell you which wheel isn't reading, chances are they'll just say like $30 or so its not something thats that complicated for someone with a decent scan tool. you're just wasting time and getting nowhere by watching youtube videos. I work as a mechanic, it literally takes about five minutes to check which wheel isn't being read by the sensor and you won't have to go through all the hassle of trying to figure it out with all these methods that are gonna get nowhere. you won't be able to spin the axle fast enough to get a significant enough voltage change to be able to tell the difference, the awd won't let you. Resistance checking will just let you know whether the sensor is ok or not, if the resistance is fine then its not your sensors.
__________________
dmitrofed is offline   Reply With Quote
Old 01-15-2013, 03:43 AM   #27
RayPooley
Registered User
 
Join Date: Jul 2012
Location: Liverpool
Posts: 1,460
My Ride: 320i SE Coupe
Resistance checking will tell you about the copper coil. It wont tell you anything about the condition of the permanent magnet in the sensor.
RayPooley is offline   Reply With Quote
Old 01-20-2013, 06:26 PM   #28
Pig_Pen
Registered User
 
Join Date: Feb 2012
Location: mn
Posts: 24
My Ride: 325xi
Despite being called cheap and told I was doing pointless stupid stuff, I wanted to post back my findings in case someone else runs into the same issue. As suspected, my abs sensors were fine. I pulled one of the bearings and they did not have the reluctor rings molded into them, causing my abs, brake and dsc light trifecta. So, anyone that is doing wheel bearings on the e46, beware, make sure the bearings you buy have the abs exciter ring molded in to them.

Peace.
Pig_Pen 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 11:56 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use