Abs / Trc Lights On

[gar is200 sport]

the abs lights on on my 99 is200se the abs stays on but the trc light is flashing had it checked and cables are connected they then pluged it in and reset it the lights went off and the trc button worked as should do I then drove round block to test and soon as touched brake pedal the lights came back on the mechanic wasn't sure if sensor or bearing so we have ordered a sensor to try it could it be anything else or have we done it in correct order theres no noises coming from bearing but if sensor dosent work will change bearing unless should try something else first what you guys think is there something to try before bearing but after sensor just if sensor dosent work that is