As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CFM IS REPORTING A POTENTIAL PROBLEM WITH #1 ENGINE EEC CHANNEL B VIBRATION ANALYSIS HEALTH MODULE(VAHM) WITHIN THE EEC. GROUNDED - YES. STEP1: ENG. 1 "B" EEC P/N 2474M64P06 S/N LPBM0878STEPS 2/3 : "AVM PART NUMBER" SHOWS "NOT LOADED" REF. B737-9 AMM 73-21-05, REMOVED/INSTALLED #1 ENG "B" EEC. ONE EEC REPLACEMENT TESTS AND CREDENTIALS COMPLETED.