Mode selector was stuck. Toggle a few times - ok. Open train doors manually - ok. ~~~~~ 3556 Mode selector was stuck. Toggle a few times - ok. Open train doors manually - ok. CE: 3556- MCH at B3 Unable to toggle MCH at M/ Line.(cbtc) NLe Checked 3556 Mode Selector Operation - OK. Cheched for FOD or Misalignment - N . AM Stopper inhibitor found too low at both cab. SIG assist to readjust inhibitor. Tested Operation - OK. Au TK 44463