'92 140 ASR box replacment

[Toxicant]

Hello all,

I had my 92 500SEL checked out for a ASR/ABS light on, he found a code for the rt front wheel sensor missing. He then checked the sensor and said it was working fine. He said the signal was present at the controlers pins so he thought the controler is bad.

I got a used controler but when I installed it the light doesn't even turn off like the other controler did, just stays on. Is there anything that needs to be done to get the used controler to learn this different car?

Just to explain the original problem, start car, lights go off. First time you hit the brake the abs kicks in and the lights come on. no traction control or abs when light is on. If I start car and take off in the snow, traction works until I hit the brakes.

Thanks

Ron