SFCC - FLAP PCU VALVEBLOCK Fault

TASK 27-51-00-810-802-A
SFCC - FLAP PCU VALVEBLOCK Fault

1. Possible Causes

VALVE BLOCK-FLAP 1 [23CV]
VALVE BLOCK-FLAP 2 [24CV]
SOLENOID VALVE
valveblock filters
aircraft wiring
SLAT/FLAP CONTR.COMP. [21CV]
SLAT/FLAP CONTR.COMP. [22CV]

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	MEGOHMMETER 100 MOHMS - MEASURING VOLTAGE 45 VDC
No specific	1	MULTIMETER - STANDARD

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 27-51-00-810-852-A	Flaps - SFCC 1 (2) Gives PCU Valveblock 23CV (24CV) Valve Sensor Message
AMM 27-50-00-866-008	Extension of the Flaps on the Ground
AMM 27-50-00-866-009	Retraction of the Flaps on the Ground
ASM 275102
ASM 275103
AMM 27-51-34-000-001	Removal of the SFCC
AMM 27-51-34-400-001	Installation of the SFCC
AMM 27-54-53-000-001	Removal of the Valve Blocks of the Power Control Unit (Flap)
AMM 27-54-53-000-002	Removal of the Solenoid Valves of the Power Control Unit (Flap)
AMM 27-54-53-000-003	Removal of the Filters of the Valve Blocks
AMM 27-54-53-400-001	Installation of the Valve Blocks of the Power Control Unit (Flap)
AMM 27-54-53-400-002	Installation of the Solenoid Valves of the Power Control Unit (Flap)
AMM 27-54-53-400-003	Installation of the Filters of the Valve Blocks

3. Fault Confirmation
Subtask 27-51-00-710-051-A

A. Test
(1) Make sure that the Post Flight Report does not show hydraulic system faults.
(2) Move the flaps AMM 27-50-00-866-008 AMM 27-50-00-866-009.
(a) Examine the SFCC, FLP ON GROUND FAULTS page for a valveblock message.
(b) If a valveblock message is shown, or the A/C has had this fault before, do the fault isolation procedure.
(c) If the fault message FLP 1 (2) PCU VALVEBLOCK 23CV (24CV) VALVE SENSOR 27-54-53 message is shown, do the TSM Task (Ref. TSM TASK 27-51-00-810-852).

4. Fault Isolation
Subtask 27-51-00-810-051-A

A. Procedure

CAUTION: MAKE SURE THAT YOU DO NOT CAUSE A SHORT CIRCUIT IN THE WIRING TO THE SOLENOID VALVES. A SHORT CIRCUIT CAN CAUSE DAMAGE TO THE SFCC(S).

(1) Do a check of the PLR for FLAP 1 (2) PCU VALVEBLOCK 23CV (24CV) VALVE SENSOR 27-54-53 message. If the message shows, do the TSM Task (Ref. TSM TASK 27-51-00-810-852).

NOTE: This message is not a CFDS Normal Mode message and shows only in SFCC reports.

(2) Do a check of the circuit resistance and circuit isolation of the extend and retract solenoid valves as follows:

NOTE: A test is not available for the Linear Variable Differential Transducer (LVDT).

(a) Get access to the electrical connector at the applicable VALVE BLOCK-FLAP 1 [23CV] or VALVE BLOCK-FLAP 2 [24CV] ,
AMM 27-54-53-000-001.
(b) Use a MULTIMETER - STANDARD to do a check of the resistance values at the connector. Make a note of the resistance values between:

For SFCC 1/ VALVE BLOCK-FLAP 1 [23CV] , (EXTEND) pins T and U, (RETRACT) pins J and H ASM 275102
For SFCC 2/ VALVE BLOCK-FLAP 2 [24CV] , (EXTEND) pins T and U, (RETRACT) pins J and H ASM 275103.

For solenoid valves with Part No. 667C0000-02, between 71 Ohms and 84 Ohms
For solenoid valves with Part No. 903A0000-01, between 53 Ohms and 60 Ohms
For solenoid valves with Part No. 1106A0000-01 or 1111A0000-01, between 53 Ohms and 60 Ohms
For solenoid valves with Part No. 5751A0000-01, between 53 Ohms and 60 Ohms.

(d) At the valveblock electrical connector, do a check for circuit isolation:
1 For the EXTEND solenoid, connect the pins U and T together.
2 For the RETRACT solenoid, connect the pins J and H together.
3 Connect one test lead of the MEGOHMMETER 100 MOHMS - MEASURING VOLTAGE 45 VDC or a 50VDC +5VDC/-5VDC Isolation Tester to the pins UT or JH and the other test lead to pin G.
4 Supply a test signal for 5 seconds then read the resistance value shown.
5 The resistance value must be more than 100 Megohms.
(3) If a SOLENOID VALVE fails one of the two tests at Para. 4.A. step (2):

Replace the applicable solenoid valve
AMM 27-54-53-000-002 and AMM 27-54-53-400-002.

(4) If the tests at Para. 4.A. step (2) are satisfactory, or the fault message included the FIN 23CV or 24CV:
(a) Examine the valveblock filters , if neccesary clean/replace them AMM 27-54-53-000-003 and AMM 27-54-53-400-003.
(5) Move the flaps (Ref. Para. 3.A. step (2)). Operate the flaps many times during the operational test to bleed the air from the system.
(6) If the fault continues, replace the applicable VALVE BLOCK-FLAP 1 [23CV] or VALVE BLOCK-FLAP 2 [24CV] ,
AMM 27-54-53-000-001 and AMM 27-54-53-400-001.
(7) If the fault continues:
(a) Get access to the electrical connector at the applicable valveblock.
(b) Release the connector.
(c) Do a check of the aircraft wiring from the applicable SFCC ARINC tray interface to the valveblock electrical connector ASM 275102 or ASM 275103.
(d) If there is a fault, do the repair.
(8) If there are no faults, interchange SFCC 1 and SFCC 2,
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(a) Move the flaps (Ref. Para. 3.A. step (2)).
(b) If the fault does not move to the other SFCC:

Install the SFCCs in their initial positions.

(c) If the fault moves with the SFCC 1(2):
1 Install the serviceable SFCC to its initial position.
2 Replace the unserviceable SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] .
3 Move the flaps (Ref. Para. 3.A. step (2)).
4 At the MCDU get access to the SFCC system status and make sure that a NO FAULTS message is shown.

5. Close-up
Subtask 27-51-00-942-051-A

A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.

Subtask 27-51-00-860-051-A

B. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:27:36 UTC