I have the following intermitant problem w/ my '92 wagon. Occasionally, immediately after starting the car and driving at low speed (i.e. out of a parking lot), the ABS dash indicator light comes on. If I turn off the car and restart it, the light stays out. I'm wondering if the light is working correctly, or is there a problem with the ABS unit? I know it performs a self-diagnostic after starting the car. Any ideas?

I agree with io... the wheel speed sensors might be dirty, although it isn't as common a problem on the 200 series as it is on the 700/900. Actually there are only two sensors, on the front wheels. THe rear wheel sensor is incorporated into the differential.

One other thing to check is the fuse connection. There is a 10amp fuse behind the felt panel underneath the passenger side of the dash. Pull it out and see if it is corroded. This will cause the same funky problem.

The ABS system takes a lot of power to do this self test, as my voltmeter drops off sharply when it does the self-test. At one point, my battery cable was loose and as a result the ABS system would hang up when it tried to power up, giving a fault light. I chased after that problem for a while until the car didn't start. Then I realized what the real problem was all about :)

It is doubtful that there is anything wrong with the system elsewhere.

most likely your wheel sensors are dirty & need to be cleaned. this is covered in the faq. i had identical symptoms, solved by driving in a tremendous rainstorm.