Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #16  
Old 11-30-2009, 11:04 PM
Registered User
 
Join Date: Aug 2008
Location: Pennsylvania
Posts: 65
I'll try to check the rear sensor when I get a chance. So are the sensors the only things that could be causing this problem? As I said, the light is off at startup, but it comes on as soon as I move forward. I've cleaned out the front ones intensely and still no difference, and the resistance in them measure fine. I just wanna make sure its a sensor problem and that I'm not barking up the wrong tree. If it is a sensor problem, I'll place my bets on the rear sensor. Is there anywhere else the rear sensor plug could be besides under the rear seat or mounted on the differential? When I get the chance, I'm gonna search for all its possible locations at once.


Last edited by 84MB500SEL; 12-01-2009 at 04:51 PM.
Reply With Quote
  #17  
Old 12-02-2009, 11:01 PM
Registered User
 
Join Date: Aug 2008
Location: Pennsylvania
Posts: 65
So does anybody have an idea on what else it could be besides a sensor problem?
Reply With Quote
  #18  
Old 12-03-2009, 09:11 AM
Registered User
 
Join Date: Nov 2007
Location: UK
Posts: 134
I had a look on WIS and the sensor is definately on the differential, not on the rear of the transmission as I thought.

On WIS the connector shown isn't a plug and socket as you would think, its a terminal block with ring connectors.

Also, it says that you need to remove the seat bench and backrest, so if you haven't already looked behind the backrest, it could be there.

Looking in the fault table, the fault for 'ABS lamp coming on whilst driving and does not go out again' is 'Wheel speed sensor cable interrupt'

So again, you really need to check the sensors and the wiring. Sensors need to be checked with an oscilloscope for a definative answer, but as previously suggested, a multimeter set onto an AC scale may give a reading when the wheel(s) are spun.

Last edited by quaid; 12-03-2009 at 09:46 AM.
Reply With Quote
  #19  
Old 12-03-2009, 11:24 PM
Registered User
 
Join Date: Aug 2008
Location: Pennsylvania
Posts: 65
Just wondering, is there a way I could test the rear sensor for a signal at the ABS unit itself, like using the multimeter on the prongs of the main plug going into the ABS unit, and avoid having to find the plug behind the seat bench? If so, does anyone know what number on the main ABS unit plug corresponds to the rear speed sensor?

Last edited by 84MB500SEL; 12-03-2009 at 11:32 PM.
Reply With Quote
  #20  
Old 12-04-2009, 05:12 AM
Registered User
 
Join Date: Nov 2007
Location: UK
Posts: 134
Pins 7 and 9 on the ABS computer (not the hydraulic unit).

Oh, and like I said earlier, you really need an oscilloscope to check the actual operation of the sensor. Do you know of a friend with one at all, or even a local shop?

You could even get one on the well known auction site usually for not much more than the shipping cost.

Last edited by quaid; 12-04-2009 at 05:30 AM.
Reply With Quote
  #21  
Old 12-06-2009, 12:35 AM
Registered User
 
Join Date: Aug 2008
Location: Pennsylvania
Posts: 65
Hmm I'll check those pins with the multimeter I have as soon as all the snow melts away and it warms up a bit (We were just bombarded by a completely unexpected snowstorm!). If the reading is good, then I guess I'll get me an oscilloscope as advised to retest all the sensors. I just wanted to test the sensors with what I have available to see if I could find the culprit before obtaining an oscilloscope. Ill stay updated on my findings...

Thanks for the wire numbers!
Reply With Quote
  #22  
Old 12-10-2009, 11:11 PM
Registered User
 
Join Date: Aug 2008
Location: Pennsylvania
Posts: 65
Quote:
Originally Posted by quaid View Post
Pins 7 and 9 on the ABS computer (not the hydraulic unit).

Oh, and like I said earlier, you really need an oscilloscope to check the actual operation of the sensor. Do you know of a friend with one at all, or even a local shop?

You could even get one on the well known auction site usually for not much more than the shipping cost.
I finally got a chance to pull out the abs computer today, but the pins on the plug are flat and have no numbers on them. Just to clarify, did you mean pins 7 and 9 on the abs control unit along the firewall under the windshield? If so, how do I know which pins are 7 and 9 since the plug isn't numbered?

Reply With Quote
Reply

Bookmarks


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
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 01:16 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page