Failure of the ELAC1 at the AP Engagement

TASK 27-93-00-810-934-A
Failure of the ELAC1 at the AP Engagement

1. Possible Causes

FMGC-1 [1CA1]
ELAC-1 [2CE1]
wiring
FMGC-2 [1CA2]
SSTU-ROLL CTL, F/O [4CE2]
SSTU-PITCH CTL, F/O [4CE4]
SSTU-ROLL CTL, CAPT [4CE1]
SSTU-PITCH CTL, CAPT [4CE3]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 27-93-00-810-983-A	Failure of the ELAC1 at the AP Engagement (New-Generation Side-Stick Unit)
TSM TASK 31-32-00-810-932-A	Failure of the Discrete Links
TSM TASK 31-32-00-810-934-A	Failure of the Digital Links
ASM 228206
AMM 22-83-34-000-001	Removal of the FMGC
AMM 22-83-34-400-001	Installation of the FMGC
ASM 228503
ASM 228602
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 27-92-41-000-002	Removal of the Transducer Units
AMM 27-92-41-400-002	Installation of the Transducer Units
AMM 27-92-41-860-801	Identification of the Side Stick Installed on the Aircraft
ASM 279244
ASM 279250
AMM 27-93-34-000-001	Removal of the ELAC
AMM 27-93-34-400-001	Installation of the ELAC
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)
AMM 29-10-00-863-003	Pressurize the Blue Hydraulic System with a Hydraulic Ground Power-Cart
AMM 29-10-00-864-003	Depressurize the Blue Hydraulic System
AMM 29-23-00-863-001	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
AMM 29-23-00-864-001	Depressurize the Green and Yellow Hydraulic Systems after Operation of the PTU
AMM 29-24-00-863-001	Pressurize the Yellow Hydraulic System with the Electric Pump
AMM 29-24-00-864-001	Depressurize the Yellow Hydraulic System
AMM 34-10-00-860-004	IR Alignment Procedure

3. Fault Confirmation
Subtask 27-93-00-860-105-A

A. Side Stick Identification
(1) Do the identification of the side stick installed on the aircraft AMM 27-92-41-860-801.
(a) If a new-generation side-stick unit is installed on the aircraft, refer to the trouble shooting procedure (Ref. TSM TASK 27-93-00-810-983).
(b) If the side stick installed on the aircraft is not a new-generation side-stick unit, continue this procedure.

Subtask 27-93-00-860-080-A

B. Job Set-Up
(1) Energize the aircraft electrical circuits AMM 24-41-00-861-002.
(2) Do the IR Alignment Procedure AMM 34-10-00-860-004.
(3) On the overhead panel 23VU:

make sure that the FLT CTL/ELAC1 and FLT CTL/SEC1 pushbutton switches are pushed (on these pushbutton switches, the OFF legend is off).

(4) On the overhead panel 24VU:

make sure that the FLT CTL/SEC2 and FLT CTL/SEC3 pushbutton switches are pushed (on these pushbutton switches, the OFF and FAULT legends are off).

(5) On the overhead panel 24VU:

release the FLT CTL/ELAC2 pushbutton switch (on this pushbutton switch, the OFF legend comes on).

(6) Pressurize the aircraft hydraulic systems AMM 29-10-00-863-003, AMM 29-23-00-863-001, AMM 29-24-00-863-001.

Subtask 27-93-00-700-170-A

C. Test
(1) On the FCU:

push the AP1 pushbutton switch to engage the AP1
push the AP2 pushbutton switch to engage the AP2.

(2) Do the BITE test of the EFCS (Ground Scanning) AMM 27-96-00-740-001.
(3) Depressurize the aircraft hydraulic systems AMM 29-10-00-864-003, AMM 29-23-00-864-001, AMM 29-24-00-864-001.

4. Fault Isolation
Subtask 27-93-00-810-183-A

A. If the F/CTL ELAC1 FAULT warning comes into view 1 second after the AP1 engagement:
(1) Replace the FMGC-1 [1CA1] AMM 22-83-34-000-001 and AMM 22-83-34-400-001.
(2) If the fault continues:

replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

(3) If the fault continues:
(a) Do the trouble shooting procedure (Ref. TSM TASK 31-32-00-810-932) related to the DSI 07 and DSI 13 signals of the ELAC1 (2CE1) ASM 279244.
If you find a defect:

repair it
do the test given in Para. 3.

If you do not find any defect, continue the trouble shooting.
(4) If the fault continues:
(a) Do the trouble shooting procedure (Ref. TSM TASK 31-32-00-810-934) related to the DGI 04 Bus of the ELAC1 (2CE1) ASM 279250, ASM 228602.
If you find a defect:

repair it
do the test given in Para. 3.

If you do not find any defect, continue the trouble shooting.
(5) If the fault continues:
(a) Do a check of the wiring of the DSO 07 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC1 (1CA1) ASM 279244

if there is continuity see Para. (b)
if there is no continuity repair the above wiring.

(b) Do a check of the wiring of the DSI 07 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC1 (1CA1) ASM 279244, ASM 228503.

if there is continuity see Para. (c)
if there is no continuity repair the above wiring.

(c) Do a check of the wiring of the DSI 13 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC1 (1CA1) ASM 279244, ASM 228503.

if there is continuity see Para. (5)
if there is no continuity repair the above wiring.

(d) Do a check and repair the wiring of the DGI 04 Bus from the ELAC1 (2CE1) COM part and MON part to the FMGC1 (1CA1) ASM 279250, ASM 228602.

Subtask 27-93-00-810-184-A

B. If the F/CTL ELAC1 FAULT warning comes into view 1 second after the AP2 engagement:
(1) Replace the FMGC-2 [1CA2] AMM 22-83-34-000-001 and AMM 22-83-34-400-001.
(2) If the fault continues:

replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

(3) If the fault continues:
(a) Do the trouble shooting procedure (Ref. TSM TASK 31-32-00-810-932) related to the DSI 10 and DSI 17 signals of the ELAC1 (2CE1) ASM 279244, ASM 228503.
If you find a defect:

repair it
do the test given in Para. 3.

If you do not find any defect, continue the trouble shooting.
(4) If the fault continues:
(a) Do the trouble shooting procedure (Ref. TSM TASK 31-32-00-810-934) related to the DGI 05 Bus of the ELAC1 (2CE1) ASM 279250, ASM 228206.
If you find a defect:

repair it
do the test given in Para. 3.

If you do not find any defect, continue the trouble shooting.
(5) If the fault continues:
(a) Do a check of the wiring of the DSO 08 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC2 (1CA2) ASM 279244

if there is continuity see Para. (b)
if there is no continuity repair the above wiring.

(b) Do a check of the wiring of the DSI 10 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC2 (1CA2) ASM 279244, ASM 228503.

if there is continuity see Para. (c)
if there is no continuity repair the above wiring.

(c) Do a check of the wiring of the DSI 17 signal from the ELAC1 (2CE1) COM part and MON part to the FMGC2 (1CA2) ASM 279244, ASM 228503.

if there is continuity see Para. (d)
if there is no continuity repair the above wiring.

(d) Do a check and repair the wiring of the DGI 05 Bus from the ELAC1 (2CE1) COM part and MON part to the FMGC2 (1CA2) ASM 279250, ASM 228602.

Subtask 27-93-00-810-185-A

C. If the F/CTL ELAC1 FAULT warning comes into view 5 seconds after the AP engagement:
(1) On the CAPT side stick, push and hold the takeover and priority pushbutton switch:
(a) On the panel 131VU, on the SIDE STICK PRIORITY/CAPT annunciator light, if the green CAPT legend comes on:

replace the SSTU-ROLL CTL, F/O [4CE2] AMM 27-92-41-000-002 and AMM 27-92-41-400-002.

1 If the fault continues:

replace the SSTU-PITCH CTL, F/O [4CE4] AMM 27-92-41-000-002 and AMM 27-92-41-400-002.

(b) On the panel 131VU, on the SIDE STICK PRIORITY/CAPT annunciator light, if the green CAPT legend does not come on:

replace the SSTU-ROLL CTL, CAPT [4CE1] AMM 27-92-41-000-002 and AMM 27-92-41-400-002.

1 If the fault continues:

replace the SSTU-PITCH CTL, CAPT [4CE3] AMM 27-92-41-000-002 and AMM 27-92-41-400-002.

Subtask 27-93-00-700-171-A

D. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:28:07 UTC