Message Name:

[ACSC1-B] LH FAN AIR VLV CMD /WRG

Message Code:

2162318ECS

The Fan Air Valve (FAV) is detected failed if one of the following conditions is met:

• Fail closed if the Pneumatic Temperature Thermostat (THC) sends an opening command to FAV and FAV remains closed
• Fail close if Pack Inlet Temperature (PIT) > 232°C for 30 sec
• Fail close if PIT > 260°C for 10 seconds
• Fail open if PIT < 150°C

• Fan Air Valve 1 (FAV) (L22)
• Pneumatic Temperature Thermostat 1 (THC) (L8)
• Pneumatic Temperature Thermostat (THC) Filter
• Air Conditioning System Controller 1 (ACSC) (A87)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None

Flight Operation Notifications Manual (FONM): None

1. Inspect, clean or replace the THC filters.
2. Perform leak check of the sense line between THC and FAV.
3. Interchange THC 1 with THC 2.

   1. If system checks are good, replace THC 1 and do close out.
   2. If fault remains, continue with next step.

4. Interchange FAV 1 with FAV 2.

   1. If system checks are good, replace FAV 1 and do close out.
   2. If fault remains, continue with next step.

5. Perform wiring checks of the wiring between ACSC and THC.

   1. If the wiring checks are not good, replace the defective associated wiring and do close out.
   2. If the wiring checks are good, continue with next step.

6. Replace ACSC 1.
7. Do close out.