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

LinkBack Thread Tools Display Modes
Old 09-30-2003, 02:53 PM
Registered User
Join Date: Sep 2003
Location: Applachian Mtns of NC
Posts: 9
300 TD Turbo - Brake sensor light on

I am having trouble with the brake sensor light. About 15,000 miles ago it was coming on, and we replaced the front brake pads. Afterwards, it stayed on, so they put in new sensors. That worked for a while, but for the last 10,000 miles, the sensor light periodically will come on, and then after some miles will go off.
I have had the brake pads checked twice, and have been told they are fine. I have also checked the level of the brake fluid and it is fine.
Now the light stays on all the time.
Any suggestions?

. 300 TD Turbodiesel 1985-W123
Reply With Quote
Old 09-30-2003, 11:18 PM
dmorrison's Avatar
Registered User
Join Date: Dec 2002
Location: Colleyville, Texas
Posts: 2,695
One of the wires going from the sensor in the pad to the unit in the car has a short. All the sensor does is provide a ground to the sensor unit. As the pad wears and the plastic cover of the sensor in the pad is ground away by the rotor, you get a ground. that is why is starts out flickering initially.
One of the wires, from the sensor at the wheel, to the sensing unit is shorting out. Try disconnecting each wheels wire harness and see if you can get it to stop. If it does, that is the wire that is shorting.

1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car
Reply With Quote
Old 10-01-2003, 07:44 AM
Registered User
Join Date: Sep 2003
Location: Applachian Mtns of NC
Posts: 9
Thank you

Dear Mr. Morrison,

Thank you very much for your help. Sounds like that would explain it. I was mainly concerned that there not be something that could be dangerous.

Sounds like something easy enough to track down, hopefully fix, or worst case, just ignore and get brakes checked at regular intervals (as most cars don't have this device anyway).

Your kindness and expertise are much appreciated.


. 300 TD Turbodiesel 1985-W123
Reply With Quote


Thread Tools
Display Modes

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 11:05 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page