Fan Air Valve of the Engine 1 Blocked in the Open Position

TASK 36-11-00-810-845-A
Fan Air Valve of the Engine 1 Blocked in the Open Position

1. Possible Causes

THERMOSTAT-FAN AIR VALVE CTL [7170HM]
wiring from the fan air valve (9HA1) to the BMC1 (1HA1)
wiring between pin A/3 of the fan air valve and the ground terminal
VALVE-FAN AIR, ENG1 [9HA1]
BMC-1 [1HA1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 36-11-34-000-001	Removal of the BMC
AMM 36-11-34-400-001	Installation of the BMC
AMM 36-11-43-000-001	Removal of the Fan-Air Valve Control-Thermostat
AMM 36-11-43-400-001	Installation of the Fan-Air Valve Control-Thermostat
AMM 36-11-54-000-001	Removal of the Fan Air Valve
AMM 36-11-54-400-001	Installation of the Fan Air Valve

3. Fault Confirmation
Subtask 36-11-00-710-134-A ** ON A/C NOT FOR ALL

A. Not applicable.

4. Fault Isolation
Subtask 36-11-00-810-093-B ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by the maintenance message THRM 7170HM1 OR FAN AIR-V 9HA1:
(1) If the temperature regulation is abnormally low (less than 180 deg.C) during climb/cruise:

Replace the THERMOSTAT-FAN AIR VALVE CTL [7170HM] AMM 36-11-43-000-001 and AMM 36-11-43-400-001.

(2) If the fault continues:

Do a check and repair the wiring from the fan air valve (9HA1) to the BMC1 (1HA1), pins A/1 and A/5 to pins AA/12A and AA/13A.

(a) If the fault continues:

Do a check and repair the wiring between pin A/3 of the fan air valve and the ground terminal.

(3) If the fault continues:

Replace the VALVE-FAN AIR, ENG1 [9HA1] AMM 36-11-54-000-001 and AMM 36-11-54-400-001.

(4) If the fault continues:

Replace the BMC-1 [1HA1] AMM 36-11-34-000-001 and AMM 36-11-34-400-001.

Subtask 36-11-00-710-135-A ** ON A/C NOT FOR ALL

B. After the subsequent flight, make sure that the fault does not continue.

[Rev.8 from Aug 2018] 2026.04.04 04:33:44 UTC