After my ABS/Trac lights came on 1995 850 Turbo, I took my car to a Volvo repair shop who analyzed that the ABS control module was bad. Instead of buying a new module, I decided to buy and install a used one myself. I cleared the faulty diagnostic code and now I get no faults (1-1-1) but the ABS/Trac dash light is still on. Does the ABS/Trac dash light need to be reset? If it does, is there a code similar to the service reset code? Any ideas what is causing the light to remain on?

Thanks

The ABS light is reset by the ABS control unit after it performs the initial test after the ignition switch is turned ON.
If the light remains ON, when you start driving the ABS unit will perform a self test at about 14 MPH, if all the inputs and outputs perform as expected, the ABS light will be turned OFF.
Since your ABS light is still ON, it means that there is still a problem with the system.
The ABS units 95 and earlier do not fail. I have not seen one fail yet. I repair a lot of 96 and newer units but never a 95 or earlier.

Wow! I learn more by reading these posts than I ever thought was possible. My daughter and I have tried to find that misterious noise we get when we first start the car and it gets to about 15 mph. It's the ABS self checker! That saves me a trip to the local dealer with a nebulous noise question.
Sorry I can't help with the trouble light. If the light is always on, the ABS unit is NOT working. Try it on a gravel road. The wires on Volvo's tend to get brittle with age, and I would check for a bad wire/ground.

Thanks for the new knowledge.
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95 850, 88 245