Volvo Repair: 1994 850T fault codes, brakes and rotors, mode selector

Question
ABS and Engine lights on. A2 codes retrieved are 232 315 545 553. Tranny arrow also flashed and there was no low gear on starting, I cycled the shift lever 20 times but no help. after parking and cooldown restarted and ran ok. A1  code was 222. Unable to get any response at all at A3. Brakes and rotors are fairly new work fine . all this has occurred over several months and  probably unrelated. What do the codes suggest and why cant I get even a 111 on A3?

Answer
Lars, Usually you read on 2 and 6.  1 and 3 arent used much.  ABS light usually is the ABS control unit that is the culprit.  VOlvo scan tool will tell you its the RR wheel sensor but we know better and know its the control unit.  Common problem with 850.  Tranny arrow flashing is usually the PNP switch on the trans and mode selector. Roger