View Full Version : Need Help - ABS and DSC Lights are On

02-09-2007, 06:18 AM
On a long trip about a month back, the DSC light in our E39 came on. We had functioning ABS then but no traction control. But now the ABS light is on too and likewise no functioning ABS.

Also on a long trip about a month back, both the ASC and ABS lights came on in our E36.

I have inspected the E39 carefully for sensor/wire trauma and no apparent damage found. This weekend I hope to disconnect sensors and measure resistance of same and look for a signal output upon rotation.

I really don’t want to have to turn it over to the dealership unless necessary. Anyone have experiences in these systems and can offer suggestions?

Thanks in advance.

02-13-2007, 10:32 AM
Wow, no comments on this yet.
Easy things to check are at the wheels, make sure the pickups are clean the the trigger (toothed) wheels are clean. Tooth brush, air hose, etc. Also cycle the connectors at the wheels, they can get beat around a bit.
Another classic is tire sizes, if your tires are non-stock and/or dissimilar, you can get abs/dsc problems. Even severely underinflated tires will change the effective diameter. Tire size problems often don't show up until you are on the highway.

02-14-2007, 01:12 PM
Thanks Joel, I'll check the triggers and sensors this weekend. In these cases the tire sizes and condition are fine. If I can't resolve, I have an appointment set for Tuesday at VOB.

I'll post status as available.

02-15-2007, 05:05 PM
The ABS/DSC control units have a high failure rate on those. They are easy to replace but they need to be coded to the car. Good luck!


02-21-2007, 08:01 PM
I was able to look at the wheel sensors over last weekend but couldn't find anything unusual. So off to VOB they went/go.

The E36 was first as my daughter is driving the M3 in next week's Tarheel school at VIR. I just picked it up from the Dealer and here's the report.

Fault Present for Throttle Actuator. Replaced Throttle Actuator and Bowden Cable. All is now well and had a chance on the way home to prove both ABS and ACS are functional.

The E39 goes there on March 6 and I'll report the findings at that time.

Thanks for the input.

03-24-2007, 11:07 AM
The E39 goes there on March 6 and I'll report the findings at that time.

Here's the E39 story: The ABS Computer indicated the ABS Pre-charge Pump Unit had failed and was replaced. The Steering Angle Sensor had also triggered a fault but after system reset seems fine. Anyway all is well now.

Not sure if it had anything to do with it; the Pump is located just under the left headlamp, just forward of the (broken at the time) fender liner. Subsequently suspect the travel to Atlanta and back in the rain had bathed the pump and subsequently induced the failure.

Nonetheless, given both failures, an ABS code reader/reset tool would be a handy thing to have. Anyone know of an available and affordable one?