# SDR ASAA2022013037324

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 30, 2022
- Submitted: February 3, 2022
- Operation: Air carrier
- Aircraft: [N483AS](https://openairdocs.org/aircraft/N483AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36350
- Aircraft time: 23,684 hours, 7,501 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 21269
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 26,766 hours, 8,252 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/ASAA2022013037324

## Discrepancy

AFTER PART ENGINE START, ON RECALL CONT CAB ZONE TEMP ILLUMINATED. RESET WITH MASTER CAUTION. GROUNDED - YES. CONTROLLER BITE CHECK RESULTED IN TCV FAULT, LH SIDE. REMOVED AND REPLACED LH TEMPERATURE CONTROL VALVE IAW B737-900 AMM 21-51-10-000-801 AND AMM 21-51-10-400-801, ETOPS GROUND FUNCTIONAL CHECK GOOD IAW AMM 21-51-00-700-803.

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