DOC AIRBUS | TSM A320FFailure of the T/R Hydraulic Isolation Valve in the closed position on the Engine 2
1. Possible Causes
· STATIC RELAY-THRUST REVERSER LOCKING CTL, ENG2 (3EG2)
· RELAY-THRUST REVERSER LOCKING POWER, ENG2 (2EG2)
· VALVE-THRUST REVERSER HYDRAULIC ISOLATION, ENG2 (50EG2)
· HCU-THRUST REV (4101KS)
· C/B-ENG2/REV/LOCK ( 1EG2 )
· C/B-ENGINE/ENG2/OIL/PRESS/AND REV SNSR/CHAN A ( 2EN2 )
· SEC-1 ( 1CE1 )
· SEC-3 ( 1CE3 )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 27-94-34-000-001 Removal of the SEC
Ref. AMM 27-94-34-400-001 Installation of the SEC
Ref. AMM 78-31-00-710-041 Operational Test of the Thrust Reverser System with the CFDS
REFERENCE DESIGNATION
Ref. AMM 78-31-51-000-010 Removal of the Thrust Reverser Hydraulic Control Unit
Ref. AMM 78-31-51-000-040 Removal of the Hydraulic Control Unit
Ref. AMM 78-31-51-400-010 Installation of the Thrust Reverser Hydraulic Control Unit
Ref. AMM 78-31-51-400-040 Installation of the Hydraulic Control Unit
Ref. AWM 78-36-03
Ref. ASM 78-37-01
Ref. AMM 78-37-51-000-010 Removal of the Thrust Reverser Hydraulic Isolation Valve
Ref. AMM 78-37-51-400-010 Installation of the Thrust Reverser Hydraulic Isolation Valve
3. Fault Confirmation
Subtask 78-37-00-865-051-A
A. Make sure that this(these) circuit breaker(s) is(are) closed:
PANEL DESIGNATION FIN LOCATION
121VU ENG2/REV/LOCK 1EG2 N45
121VU ENGINE/ENG2/OIL/PRESS/AND REV
SNSR/CHAN A
2EN2 N42
Subtask 78-37-00-710-052-A
B. Test
(1) Make sure that the HCU is not deactivated.
(2) Do the operational test of the thrust reverser system (2A and 2B) (MENU mode test) Ref.
AMM 78-31-00-710-041 . Make sure that the hydraulic pressure is correct during the test. The
pressure must not drop below the advisory threshold.
NOTE: If the test gives the maintenance message HCU, T/R SOV/HCU/HC do the test again with a
hydraulic ground cart or do the operational test of the thrust reverser without CFDS with engine
running Ref. AMM 78-31-00-710-041 . If you do the test with an engine ground run, enter
a new flight number in the FMGC menu via the MCDU keypad to get a Post Flight Report
(PFR) after the test. If warning ENG 2 REVERSER FAULT and maintenance message HCU,
T/R SOV/HCU/HC are shown during the test, do the following trouble shooting procedure. If
they are not shown during the test or are not recorded in the Post Flight Report (PFR) after
the ground run, no further action is required.
4. Fault Isolation
Subtask 78-37-00-810-051-A
A. This fault message is generated if the EEC detects no pressurization of the thrust reverser HCU after a
deploy command of the thrust reverser. This indicates either a thrust reverser isolation valve (50EG2)
failure to open or an HCU failure. The EEC cannot determine which one of the two items of equipment has
failed as the thrust reverser isolation valve and the HCU are installed in series, while the EEC uses the
HCU pressure switch for monitoring Ref. ASM 78-37-01.
CAUTION: MAKE SURE THAT THERE IS NO HYDRAULIC PRESSURE WHILE YOU DO THIS
TEST. PUT A WARNING NOTICE IN THE COCKPIT TO TELL PERSONS NOT TO PRESSURIZE
THE HYDRAULIC SYSTEMS.
(1) If the test does not give the maintenance message T/R SOV/HCU/HC but the fault message is shown
again on the subsequent flights:
· replace the STATIC RELAY-THRUST REVERSER LOCKING CTL, ENG2 (3EG2) .
(a) If the fault continues:
· replace the RELAY-THRUST REVERSER LOCKING POWER, ENG2 (2EG2) .
(2) If the test gives the maintenance message T/R SOV/HCU/HC or the thrust reverser does not open
normally or stow during the test:
· replace the STATIC RELAY-THRUST REVERSER LOCKING CTL, ENG2 (3EG2) .
(a) If the fault continues:
· replace the RELAY-THRUST REVERSER LOCKING POWER, ENG2 (2EG2) .
(b) If the fault continues:
· make sure that you have correctly exited the FADEC menu mode,
· disconnect the electrical connector from the thrust reverser isolation valve (50EG2),
· on the overhead panel 50VU, push and release the P/BSW-ENG/FADEC GND PWR/2 (7KS2)
the ON legend comes on,
· set the engine 2 throttle control lever to the reverse position. Make sure that the throttle control
lever of the opposite engine is in the idle position,
· do a check for ground at pin A/2 of the thrust reverser isolation valve (50EG2).
1 If there is no ground:
· repair the wiring or the ground terminal 480VN2 Ref. AWM 78-36-03.
2 If there is ground:
· do a check for 115VAC between pins 1 and 2 of the connector on the harness side.
a If there is 115VAC:
· replace the VALVE-THRUST REVERSER HYDRAULIC ISOLATION, ENG2
(50EG2) Ref. AMM 78-37-51-000-010 and Ref. AMM 78-37-51-400-010 .
If the fault continues:
· replace the HCU-THRUST REV (4101KS) Ref. AMM 78-31-51-000-010 and Ref.
AMM 78-31-51-400-010 .
b If there is no 115VAC:
· on the overhead panel 50VU, push the P/BSW-ENG/FADEC GND PWR/2 (7KS2) the
ON legend goes off,
· do a continuity check of the electrical wiring between the thrust reverser isolation
valve (50EG2) pin A/1 and the power relay 2EG2 pin A/A2.
c If the wiring is not correct:
· repair as required.
d If the wiring is correct:
· remove the static relay (3EG2) and the power relay (2EG2) from their base on
120VU.
· on the overhead panel 50VU, push and release the P/BSW-ENG/FADEC GND
PWR/2 (7KS2) the ON legend comes on,
· with the engine 1 throttle control lever still in reverser position, do a check for 115VAC
at pin A/B1 of the relay base 2EG2.
e If there is no 115VAC:
· repair the wiring or replace the C/B-ENG2/REV/LOCK ( 1EG2 ) .
f If there is 115VAC:
· do a check for 28VDC at pin A/X of the relay base 3EG2.
g If there is no 28VDC:
· repair the wiring or replace the C/B-ENGINE/ENG2/OIL/PRESS/AND REV SNSR/
CHAN A ( 2EN2 ) .
h If there is 28VDC:
· do a check for ground at pin A/X2 of the relay base 2EG2 and pin A/Z of the relay
base 3EG2.
i If there is no ground:
· repair the wiring.
j If there is ground:
· on the overhead panel 50VU, push the P/BSW-ENG/FADEC GND PWR/2 (7KS2) the
ON legend goes off,
· set the engine 2 throttle control lever to idle position,
· do a check of the wiring continuity between the static relay (3EG2), the SEC1 (1CE1)
and the SEC3 (1CE3).
k If the wiring is correct:
· make sure that there is no ground at pin AB/15F on the SEC1 (1CE1) and the SEC3
(1CE3) Ref. ASM 78-37-01.
· look for any FCDC or radio altimeter failure (on the Post Flight Report (PFR)) causing
SEC output malfunction (TSM chapter 27).
l If no external failure to the SECs is found:
· replace successively the SEC-1 ( 1CE1 ) then the SEC-3 ( 1CE3 ) Ref.
AMM 27-94-34-000-001 and Ref. AMM 27-94-34-400-001 .
(3) If thrust reverser operation (deploy and stow) was normal during aircraft operation and during the test
but the maintenance message T/R SOV/HCU/HC is confirmed:
· replace the HCU (4101KS2) Ref. AMM 78-31-51-000-040 and Ref. AMM 78-31-51-400-040 .
Subtask 78-37-00-710-053-A
B. Do the test given in Para. 3.B.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues. [Rev.6 from Feb 2017] 2026.04.04 04:38:20 UTC