As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING T.C. # 08031001, AEVM DISPLAYED MSG "N1 TACHO LOSS E1," ON LEGS 0, 1, AND 2. SYSTEM TEST OK. GROUNDED - YES. REMOVED AND REPLACED N1 SPEED SENSOR PER B737-800 AMM 77-11-01-400-801-F00. OPS AND LEAK CHECK GOOD. NO FAULTS LOGGED.