Brake noise, then ABS light
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Joined: Aug 2003
Posts: 21
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From: N. Alabama
Brake noise, then ABS light
An annoying problem has cropped up on my 93 190E. Occasionally while braking, I hear a noise like a spring expanding "SPROOOOOOOONG", sounds like it come from at or under the brake pedal, then the yellow ABS dash light comes on. It will remain on until I stop, turn off the ignition, then restart. Then all is normal again, the light goes out, sometimes for days until it happens again. The brakes seem to be operating normally at all times and there is no pattern that I can see. Any ideas? Thanks, Don
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Joined: Aug 2002
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
My guess is that the ABS sensors (two each front wheel and one in the differential gear box) are not working properly, and activating the ABS lights and the weird noise. You can measure the resitance to locate the failure, as a first check. The front sensors shall have a resitance of 1.1-2.3 kOhm and the single rear sensor 0.6 - 1.6 kOhm. The next check wouldbe to turn the wheel as fast as possible an measure the voltage the sensor generates which shall be higerh than 100 mVolts. If this is not possible the sensors need to be replaced. Sometime cleaning may help, but before you clean them put them back , check again and find out it was not sufficient, get your self a set of new once.
The coax-connectors of the sensors can be found on the wheel well (right and left) under the hood for the front sensors, and under the rear seat for the rear sensor.
The coax-connectors of the sensors can be found on the wheel well (right and left) under the hood for the front sensors, and under the rear seat for the rear sensor.
