# SDR ASAA2022020837371

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 8, 2022
- Submitted: February 11, 2022
- Operation: Air carrier
- Aircraft: [N408AS](https://openairdocs.org/aircraft/N408AS), registered now
- Make and model: Boeing 737-900ER
- Registry model: [Boeing 737-900ER](https://openairdocs.org/model/boeing-737-900er) (OpenAirDocs)
- Aircraft serial: 41732
- Aircraft time: 33,743 hours, 10,729 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 1538
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 87,811 hours, 44,478 cycles
- Stage of operation: TX
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2022020837371

## Discrepancy

DURING PREFLIGHT LEFT PACK LIGHT WAS ILLUMINATED. GROUNDED - YES. ACCOMPLISHED #1 TEMP CONTROLLER BITE TEST SHOWS THIS PACK TCV UNABLE TO RESET FAULT. SWAPPED TEMP CONTROLLER AND FAULT STAYED WITH #1 POSITION. SWAPPED CONTROLLER BACK TO ORIGINAL POSITIONS REF B737-900 AMM 21-61-20. BITE TEST STILL SHOWS THIS PACK TCV AND PACK LIGHT WILL NOT RESET. REF B737-900 FIM 21-62 TASK 801. REMOVED AND REPLACED TEMP CONTROL VALVE IAW AMM 21-51-10-400-801. OPS TEST GOOD, LEAK CHK GOOD. GROUND VERIFICATION SUCCESSFUL.

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