# SDR CALA2026091819530

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 16, 2026
- Submitted: September 18, 2026
- Operation: Air carrier
- Aircraft: [N66893](https://openairdocs.org/aircraft/N66893), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 42197
- Aircraft time: 33,439 hours, 12,425 cycles
- Engine: Cfmint CFM567B27
- System (JASC): [7397 · Engine Fuel System Wiring](https://openairdocs.org/jasc/7397)
- Part: Wire Harness
- Condition: Faulted
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026091819530

## Discrepancy

FUEL FILTER BYPASS LIGHT FOR NR 1 ENGINE.  DEBRIEFED CREW,  FUEL FILTER BYPASS LIGHT CAME ON FOR ABOUT 30 MINS, FLIGHT ATTENDANTS REPORTED A FUEL ODOR IN CABIN. THE FUEL BYPASS LIGHT EXTINGUISHED DURING DESCENT & REPORTED THE FUEL ODOR DIMINISHED. THE LIGHT REMAINED EXTINGUISHED FOR THE REMAINDER OF FLIGHT. TOTAL FUEL IS 18.6, PERFORMED EEC BITE ON NR 1 ENG.  FOUND MM 73-31071 FUEL FILTER SIGNALS DIASAGREE NR 1 ENG DUAL CHANNEL FAULT.   NR 1 ENGINE EEC GROUND TEST PASSED AND FUEL FILTER LIGHT EXTINGUISHED.   DUE TO REPORTS OF FUEL FILTER BYPASS LIGHT BEING ILLUMINATED IN FLIGHT,  PERFORMED FIM TASK 73-05 TASK 801 UP TO STEP E, SUBTASK 4, J8 HARNESS REPLACEMENT. EEC BITE TEST GAVE FAULT CODE 73-31071 NR 1 ENG DUAL CHANNEL FAULT. BOTH FUEL FILTER DIFFERENTIAL PRESSURE SWITCH & FUEL FILTER WERE CHANGED VERY RECENTLY AT ANOTHER STATION. THE NEXT STEP IN THE FIM WAS TO DO A WIRING CHECK OF THE ENG 1 FUEL FILTER LIGHT, DEU1 AND DEU2. NO WIRING ISSUES WERE FOUND.   REMOVED AND REPLACED ENG 1 J8 WIRING HARNESS, IAW AMM 73-21-06, EEC TEST AND TEST 12 ACTUATORS TESTALL OPS CHK COMPLETE, NO FAULTS FOUND, IDLE LEAK CHK GOOD, IAW AMM 73-21-06.

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