Pack 2 Flow Control Valve (Pack 2 Flow Control Unit) Fault

TASK 21-51-00-810-804-A
Pack 2 Flow Control Valve (Pack 2 Flow Control Unit) Fault

1. Possible Causes

P2 FLOW CTL VALVE [8HB]
FLOW CTL UNIT - PACK 2 [24HB]
RELAY-R PACK CLOSE [12HB]
RELAY-DISAGREE (R FCV) [14HB]
BOARD-ANN LT TEST & INTFC [20LP]
P/BSW-AIR COND/PACK 2 [6HB]
RELAY-ENGINE START [16HB]
ENG/APU FIRE PNL [1WD]
RELAY-RAM AIR CLOSE CTL [3HZ]
RELAY-ENGINE START [17HB]
P2 CONTROLLER [27HH]
BOARD-ANN LT TEST & INTFC [12LP]
CONT-AIR COND SYSTEM 2 [57HH]
wiring
REHEATER [11HM3]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-51-00-200-001	Delta P Sense Lines Torque Check and Inspection
AMM 21-51-00-710-002	Operational Test of the Flow Control and Indicating System
ASM 215101
ASM 215102
AWM 215105
AMM 21-51-51-000-001	Removal of the Pack Flow-Control Valve/ Pack Flow-Control Unit
AMM 21-51-51-400-001	Installation of the Pack Flow-Control Valve/ Pack Flow-Control Unit
AMM 21-52-31-000-001	Removal of the Reheater
AMM 21-52-31-400-001	Installation of the Reheater
AMM 21-61-00-710-001	Operational Test of the Pack Temperature-Control System
AMM 21-61-34-000-001	Removal of the Pack Controller
AMM 21-61-34-000-002	Removal of the Air-Conditioning System Controller
AMM 21-61-34-400-001	Installation of the Pack Controller
AMM 21-61-34-400-002	Installation of the Air-Conditioning System Controller
AMM 73-25-34-710-040	Operational Test of the Engine Interface Unit
AMM 73-25-34-710-043	Operational Test of the Engine Interface Unit

3. Fault Confirmation
Subtask 21-51-00-710-056-A

A. Test
(1) Do the operational test of the flow control and indication system AMM 21-51-00-710-002.
(2) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.

4. Fault Isolation
Subtask 21-51-00-810-054-A

A. If the test is OK, no other maintenance action is necessary.

Subtask 21-51-00-810-055-B ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

replace the P2 FLOW CTL VALVE [8HB] (referred to as FCV (8HB)) AMM 21-51-51-000-001 and AMM 21-51-51-400-001.

Subtask 21-51-00-810-055-C ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

replace the FLOW CTL UNIT - PACK 2 [24HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.

Subtask 21-51-00-810-090-A ** ON A/C NOT FOR ALL

C. If the fault continues:
- do the inspection of the delta P sense lines AMM 21-51-00-200-001.

Subtask 21-51-00-810-074-A ** ON A/C NOT FOR ALL

D. If the fault continues:

do a check of the RELAY-R PACK CLOSE [12HB] and replace it if necessary ASM 215102.

(1) If the fault continues:

do a check of the RELAY-DISAGREE (R FCV) [14HB] and replace it if necessary ASM 215102.

(2) If the fault continues:

do a check of the BOARD-ANN LT TEST & INTFC [20LP] and replace it if necessary ASM 215102.

(3) If the fault continues:

do a check of the P/BSW-AIR COND/PACK 2 [6HB] and replace it if necessary ASM 215102.

(4) If the fault continues:

do the operational test of the engine interface unit (1KS2) AMM 73-25-34-710-040.

(a) If the test gives a different maintenance message refer to the Fault Symptom List.
(5) If the fault continues:

do a check of the RELAY-ENGINE START [16HB] and replace it if necessary ASM 215102.

(6) If the fault continues:

do a check of the ENG/APU FIRE PNL [1WD] and replace it if necessary ASM 215102 and ASM 215102.

(7) If the fault continues:

do a check of the RELAY-RAM AIR CLOSE CTL [3HZ] and replace it if necessary ASM 215102.

(8) If the fault continues:

do a check of the RELAY-ENGINE START [17HB] and replace it if necessary ASM 215102.

(9) If the fault continues:

replace the P2 CONTROLLER [27HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.

Subtask 21-51-00-810-082-A ** ON A/C NOT FOR ALL

E. If the fault continues:

do a check and repair the wiring ASM 215101 between:
the FCV (8HB) and PC (27HH),
the FCV (8HB) and ground,
the RELAY (12HB) and the FCV (8HB),
the RELAY (14HB) and the FCV (8HB) and,
the RELAY (14HB) and the PC (27HH).
do a check and repair the wiring AWM 215105 between:
the circuit connection 210VT connector U and the PC (27HH) connector AB pin 7A,
the circuit connection 210VT connector T and RELAY (14HB) connector A pin A2.

(1) If the fault continues:

replace the REHEATER [11HM3] AMM 21-52-31-000-001 and AMM 21-52-31-400-001.

Subtask 21-51-00-810-074-B ** ON A/C NOT FOR ALL

F. If the fault continues:

do a check of the BOARD-ANN LT TEST & INTFC [12LP] and replace it if necessary ASM 215101.

(1) If the fault continues:

do a check of the P/BSW-AIR COND/PACK 2 [6HB] and replace it if necessary ASM 215101.

(2) If the fault continues:

do the operational test of the engine interface unit (1KS2) AMM 73-25-34-710-043.

(a) If the test gives a different maintenance message refer to the Fault Symptom List.
(3) If the fault continues:

do a check of the ENG/APU FIRE PNL [1WD] and replace it if necessary ASM 215101 and ASM 215102.

(4) If the fault continues:

do a check of the RELAY-RAM AIR CLOSE CTL [3HZ] and replace it if necessary ASM 215101.

(5) If the fault continues:

replace the CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.

Subtask 21-51-00-810-082-B ** ON A/C NOT FOR ALL

G. If the fault continues:

do a check and repair the wiring ASM 215101 between:
the FCU2 (24HB) and ACSC2 (57HH) and,
the FCU2 (24HB) and ground.

(1) If the fault continues:

replace the REHEATER [11HM3] AMM 21-52-31-000-001 and AMM 21-52-31-400-001.

Subtask 21-51-00-710-057-A

H. Do the test as given in the Para. 3.A.

5. Close-up
Subtask 21-51-00-860-053-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:24:46 UTC