Darn ABS & ASR lights - on again!!! - PeachParts Mercedes-Benz Forum

sura · #1 06-01-2007, 09:45 PM

Car: 1996 S420 (W140)

For the last 3 or 4 months the ABS & ASR lights would suddenly come on. Each time it turns out to be the fuse controlling the brake light/cruise control/ABS circuits. When I replace the fuse, all is ok again for 2 to 3 weeks. I've already replaced the stop light switch.

Anyone had this happen to them? I don't know where to look.

Thanks.

pistonhead · #2 06-02-2007, 03:17 PM

Have you had the fault memory erased after repair has been effected?

sura · #3 06-02-2007, 04:27 PM

No, I have not. Is this something requiring a dealer? I had the OBD II codes read but there were none.

#4 11-26-2007, 03:26 PM

I have a 1991 300 SE. Dealership and indedpendent
mechanic cannot find the problem with ABS/ASR light
coming on. ASR engages, then ABS light comes on and
stays on. When brakes applied, front of car seems to
slide at the end of braking. HELP

JFawcett · #5 03-03-2008, 10:59 AM

I am having something like this on my 1997 S-500 - the ABS, BRAKE, Brake Pad Sensor light all come on and the speedometer registers 0 MPH. This first happened on freeway - no brake action (but brakes worked fine).
Spoke to mechanic and he thinks it is a wheel speed sensor??? Anyone ever heard of this?

iwrock · #6 03-03-2008, 11:03 AM

I have heard of the wheel speed sensor, but I would first look into your speedometer problems. Without the input from the speedo, your car will be confused, as it takes the data from the speedo and compares it to the wheel speed sensors.

JFawcett · #7 03-03-2008, 04:15 PM

The speedometer gets input from the wheel sensors. On the 140 the ABS, Speedometer and Anti-Slip get input from wheel sensors and (I think) the transmission. I don't think there is any comparison going on between speedometer and the wheels......
Can anyone tell me where the sensors are?

oestek · #8 03-26-2008, 11:05 PM

The wheel speed sensors in the front are located on the spindles behind the brake dust shields... they point at the little reluctor teeth on the back side of the hub. Grease and dirt can cause them to get confused... I've had this happen before. Did a wheel bearing job, got grease on the hub, and the ABS and ASR lights all came on, the car did weird things, etc. It was just grease between the teeth making the sensor read incorrectly.