ABS Light just came up on Dash
 

I have a 1987 300D Turbo with 250K miles. I have had no brake problems or abnormal tire wear on the tires with 60K miles. The ABS light just came on the dash. I also noticed that when I break, the ABS will kick-in just before the car stops, even when the wheels do not lock up. I suspect that one or more ABS sensors have gone bad. I believe that there is one sensor on each wheel. Can someone provide advise about the probable cause of this as well as a plan for troubleshooting? I checked the fuses and all were good.

Seems like an unrelated question but it's not; how does it run when first started cold?
Gilly

Ooops, it's a diesel, disregard. Reason I ask is a bad OVP can cause this, it would also run poorly when cold on a gas engine like a 300E. I'd check the OVP fuse, could still be a bad OVP though, but check for a blown fuse. Are the tires all the same size? I agree it could be a bad or dirty ABS sensor.
Gilly