# SDR ASAA2022032337794

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 23, 2022
- Submitted: March 30, 2022
- Operation: Air carrier
- Aircraft: [N926AK](https://openairdocs.org/aircraft/N926AK), registered now
- Make and model: Boeing 737-9
- Registry model: [Boeing 737-9](https://openairdocs.org/model/boeing-737-9) (OpenAirDocs)
- Aircraft serial: 43314
- Aircraft time: 666 hours, 199 cycles
- Engine: Ge CFM567B24
- System (JASC): [4920 · APU Core Engine](https://openairdocs.org/jasc/4920)
- Part: Ecu
- Part number: 7072086010
- Part serial: 6505150206203
- Condition: Inoperative
- Location: Aft Cargo Compar
- Part time: 702 hours, 209 cycles
- Stage of operation: NR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2022032337794

## Discrepancy

APU FAULT LIGHT ILLUMINATES ON ATTEMPTED APU START. GROUNDED - YES. ACCOMPLISHED APU BITE TEST, FOUND ACTIVE MAINTENANCE MESSAGE 49-89002 " ONBOARD MAINTENANCE FUNCTION HAS NO INPUT FROM APU ECU" PER B737-9 IFIM 49-00-00-810-817, REMOVED AND REPLACED APU ELECTRONIC CONTROL UNIT REF B737-9 AMM 49-61-12/401. START APU AND PERFORMED APU BITE TEST, NO ACTIVE FAULT NOTED.

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