# SDR ASAA2013052894922

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 28, 2013
- Submitted: May 30, 2013
- Operation: Air carrier
- Aircraft: [N423AS](https://openairdocs.org/aircraft/N423AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 35206
- Aircraft time: 151 hours, 35 cycles
- System (JASC): [4900 · Airborne Auxiliary Power Unit (APU) System](https://openairdocs.org/jasc/4900)
- Part: Warning Message
- Condition: False Indication
- Location: Apu
- Stage of operation: TX
- How discovered: O
- Nature of condition: N
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2013052894922

## Discrepancy

APU MAINT LIGHT ILLUMINATED ON APU START.  ACFT GROUNDED.  PERFORMED APU BITE PROCEDURE.  REF FIM 49-60 TASK 801.  FOUND MX MESSAGE 49-91227.  PERFORMED FIM 49-90, TASK 804, FAULT ISOLATION, STEP E.  NO MX MESSAGE ON CURRENT STATUS PAGE.  DETERMINED TO BE AN INTERMITTENT FAULT.

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