08/10/21
Message Overview:
Message Description:
The TEMPERATURE CONTROL VALVE is detected failed in the open position.
Possible Causes:
- Temperature Control Valve (MPE7)
- Integrated Air System Control 2 (IASC2) (A56)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Integrated Air System (IAS) Controller | AMM 21-31-01-000-801 |
| Installation of the Integrated Air System (IAS) Controller | AMM 21-31-01-400-801 |
| Operational Test of the Integrated Air System (IAS) Controller | AMM 21-31-01-710-801 |
| Installation of the Temperature Control Valve | AMM 21-52-33-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Wire Repair | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset system power and verify if the discrepancy still exists.
- Verify the closed commanded position when the Temperature Control Valve MPE7 has failed.
- Valve position can be viewed through the IASC LRU test pages. Interrogate the respective IASC to view valve position and bleed air pressure.
The indicated valve position can be verified against the Bleed Valve status page by comparing the indication to the valves mechanical visual indicator. - Check the wiring between the #2 Integrated Air System Controller and the #2 flow control valve MPE4. If the switch is suspected, check the IASC #1 (A56) for proper switch indication of the effective flow control valve (FCV will provide a ground to the IASC for closed, and open circuit for the valve being open) IAW WM 21-51-09.
- Interchange or replace the suspected Temperature Control Valve IAW TASK 21-52-33-400-801.
- Suspect the #2 IAS controller, remove and replace per AMM TASK 21-31-01-000-801, TASK 21-31-01-400-801.
- Operational Test IAW AMM TASK 21-31-01-710-801.
