What was found
ENG1&ENG2 FIREX BTL B FAIL EICAS MESSAGE DISPLAYED DURING TAXI. REMOVED FROM SERVICE. FOUND FAULT 26210044UTI. C/W E175 FIM 26-21-00-810-810-A. FAULT ISOLATION RESET TEST FAILED. FAULTS REMAIN.REMOVED AND REPLACED GENERIC I/O MODULE MAU 3 IAW E175 AMM 31-41-06-000-801-A/400-801-A. OPS CHECK GOOD, ORIGINAL FAULT REMAINED. REMOVED AND REPLACED ENG FIRE BOTTLE B IAW E175 AMM 26-21-03-000-801-A/400-801-A. OLD BOTTLE CORTRIDGES WERE SWAPPED TO NEW BOTTLE IAW AMM 26-21-07-000-801-A/400-801-A. ENG FIRE BOTTLE B OPS TEST GOOD. FAULT CLEARED. AIRCRAFT GOOD FOR SERVICE.