GEN 1 FAULT Warning without Associated Message on the ECAM or with Fault Message SDAC1/2: NO DATA FROM GCU 1 on the PFR

TASK 24-00-00-810-819-A
GEN 1 FAULT Warning without Associated Message on the ECAM or with Fault Message SDAC1/2: NO DATA FROM GCU 1 on the PFR

1. Possible Causes

GCU-1 [1XU1]
P/BSW-ELEC/GEN 1 [3XU1]
RELAY-GLC 1 AUX CTL [4XU1]
wiring
GLC-1 [9XU1]
BTC-1 [11XU1]
RELAY [20XU]
SDAC-1 [1WV1]
SDAC-2 [1WV2]
IDG-ENG 1 [4000XU1]
IDG [4000XU]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 24-21-51-000-040	Removal of the Integrated Drive Generator - IDG 1(2)
AMM 24-21-51-000-803	Removal of the Integrated Drive Generator - IDG 1(2)
AMM 24-21-51-400-040	Installation of the Integrated Drive Generator - IDG 1(2)
AMM 24-21-51-400-803	Installation of the Integrated Drive Generator - IDG 1(2)
ASM 242201
ASM 242202
AMM 24-22-34-000-001	Removal of the GCU-1(2)
AMM 24-22-34-400-001	Installation of the GCU-1(2)
AMM 24-22-55-000-001	Removal of the Contactors
AMM 24-22-55-400-002	Installation of the Contactors
AMM 24-41-00-740-002	Operational Check of the GAPCU via the CFDS
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002	De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC
AMM 31-60-00-860-001	EIS Start Procedure
AMM 31-60-00-860-002	EIS Stop Procedure
AMM 71-00-00-710-003	Engine Automatic Start
AMM 71-00-00-710-028	Engine Shutdown
AMM 71-00-00-860-814	Shutdown of the Engine
AMM 71-00-00-860-823	Start the Engine (Normal Automatic Start)

3. Fault Confirmation
Subtask 24-00-00-710-060-A ** ON A/C NOT FOR ALL

Stop the engine 1 AMM 71-00-00-710-028 and do the trouble shooting given in Para. 4.A.

(b) If the GEN1 parameters are correct and the load is different from zero percent:

Stop the engine 1 AMM 71-00-00-710-028 and do the trouble shooting given in Para. 4.B.

Subtask 24-00-00-710-060-H ** ON A/C NOT FOR ALL

A. Test
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
(3) Start the engine 1 AMM 71-00-00-710-003.
(4) On the ECAM control panel, push the ELEC key (on the lower ECAM DU, the ELEC page comes into view).
(5) On the lower ECAM DU, read the GEN1 parameters (voltage, frequency and load).
(a) If the GEN1 parameters are not correct:
1 Stop the engine 1 AMM 71-00-00-710-028.
2 On the ELEC panel 35VU, release the GEN 1 pushbutton switch (the OFF legend comes on).
3 Do this test:

ACTION	RESULT
On the MCDU: Push the line key adjacent to the CFDS indication.	On the MCDU: The CFDS MENU page comes into view.
On the MCDU, on the CFDS MENU page: Push the line key adjacent to the SYSTEM REPORT/TEST indication.	On the MCDU: The SYSTEM REPORT/TEST page comes into view.
On the MCDU, on the SYSTEM REPORT/TEST page: Push the line key adjacent to the ELEC indication.	On the MCDU: The SYSTEM REPORT/TEST/ELEC page comes into view.
On the MCDU, on the SYSTEM REPORT/TEST/ELEC page: Push the line key adjacent to the AC GEN indication.	On the MCDU: The EPGS page comes into view.
On the MCDU, on the EPGS page: Push the line key adjacent to the TROUBLE SHOOTING DATA indication.	On the MCDU: The EPGS TROUBLE SHOOTING DATA page comes into view.
On the MCDU, on the EPGS TROUBLE SHOOTING DATA page: Push the line key adjacent to the GCU 1 indication.	On the MCDU: The GCU 1 TROUBLE SHOOTING DATA page comes into view.

a If the TSD GCU is NOT AVAIL:

Do the trouble shooting given in Para. 4.A.

b If the TSD GCU is AVAIL and the TSD 113 OF3_TRIP fault code is shown:

Do the trouble shooting given in Para. 4.C.

c If the TSD GCU is AVAIL but the TSD 113 OF3_TRIP fault code is not shown:

Do the trouble shooting given in Para. 4.A.

(b) If the GEN 1 FAULT warning message is shown, the GEN1 parameters are correct and the load is different from zero percent:

Stop the engine 1 AMM 71-00-00-710-028 and do the trouble shooting given in Para. 4.B.

Subtask 24-00-00-710-060-I ** ON A/C NOT FOR ALL

A. Test
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
(3) Start engine 1 AMM 71-00-00-860-823.
(4) On the ECAM control panel, push the ELEC key (on the lower ECAM DU, the ELEC page comes into view).
(5) On the lower ECAM DU, read the GEN1 parameters (voltage, frequency and load).
(a) If the GEN1 parameters are not correct:
1 Stop engine 1 AMM 71-00-00-860-814.
2 In the cockpit, on the ELEC panel 35VU:

Release the GEN 1 pushbutton switch (the OFF legend comes on).

3 Do this test:

ACTION	RESULT
On the MCDU: Push the line key adjacent to the CFDS indication.	On the MCDU: The CFDS MENU page comes into view.
On the MCDU, on the CFDS MENU page: Push the line key adjacent to the SYSTEM REPORT/TEST indication.	On the MCDU: The SYSTEM REPORT/TEST page comes into view.
On the MCDU, on the SYSTEM REPORT/TEST page: Push the line key adjacent to the ELEC indication.	On the MCDU: The SYSTEM REPORT/TEST/ELEC page comes into view.
On the MCDU, on the SYSTEM REPORT/TEST/ELEC page: Push the line key adjacent to the AC GEN indication.	On the MCDU: The EPGS page comes into view.
On the MCDU, on the EPGS page: Push the line key adjacent to the TROUBLE SHOOTING DATA indication.	On the MCDU: The EPGS TROUBLE SHOOTING DATA page comes into view.
On the MCDU, on the EPGS TROUBLE SHOOTING DATA page: Push the line key adjacent to the GCU 1 indication.	On the MCDU: The GCU 1 TROUBLE SHOOTING DATA page comes into view.

a If the TSD GCU is NOT AVAIL:

Do the trouble shooting given in Para. 4.A.

b If the TSD GCU is AVAIL and the TSD 113 OF3_TRIP fault code is shown:

Do the trouble shooting given in Para. 4.C.

c If the TSD GCU is AVAIL but the TSD 113 OF3_TRIP fault code is not shown:

Do the trouble shooting given in Para. 4.A.

(b) If the GEN 1 FAULT warning message is shown, the GEN1 parameters are correct and the load is different from zero percent:

Stop engine 1 AMM 71-00-00-860-814 and do the trouble shooting given in Para. 4.B.

4. Fault Isolation
Subtask 24-00-00-810-070-A ** ON A/C NOT FOR ALL

A. If, on the lower ECAM DU, the GEN1 parameters are not correct:

Replace the GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

(1) If the fault continues:

Do a check of the contacts of the ELEC/GEN 1 pushbutton switch (3XU1) for correct operation ASM 242202.

(a) If the contacts do not operate correctly:

Replace the P/BSW-ELEC/GEN 1 [3XU1] .

(b) If the contacts operate correctly:

Replace the RELAY-GLC 1 AUX CTL [4XU1] .

1 If the fault continues:

Do a check of the wiring for an open circuit between pin A/7A of the GCU-1 (1XU1) and the ground ASM 242202.

a If the wiring is not correct:

Repair the wiring.

b If the wiring is correct:

Replace the GLC-1 [9XU1] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

c If the fault continues:

Replace the BTC-1 [11XU1] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

d If the fault continues:

Replace the RELAY [20XU] .

e If the fault continues:

Do a check and repair the wiring ASM 242202 between:
. Pin AA/12C of the GCU-1 (1XU1) and pin A/X1 of the GLC-1 auxiliary control relay (4XU1) through the ELEC/GEN1 pushbutton switch (3XU1) and the relay function (20XU)
. Pin A/X2 of the GLC-1 auxiliary control relay (4XU1) and the ground
. Pin B/3 of the GLC-1 (9XU1)and pin AB/2D of the GCU-1 (1XU1) through the BTC-1 (11XU1) and the GLC1 auxiliary control relay (4XU1)
. Pin B/5 of the GLC-1 (9XU1) and the ground.

Subtask 24-00-00-810-070-B ** ON A/C NOT FOR ALL

A. If the TSD GCU is NOT AVAIL or if the TSD GCU is AVAIL but the TSD 113 OF3_TRIP fault code is not shown:

Replace GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

(1) If the fault continues:

Do an operational test of the GAPCU with the CFDS AMM 24-41-00-740-002.

(a) If the BITE test gives the maintenance message TEST FAILED:

Remove GCU1 AMM 24-22-34-000-001.

1 Do a check for a ground signal at ASM 242202:

Pin AA/8A of GCU1 (1XU1)
Pin AA/2E of GCU1 (1XU1)
Pin AA/4G of GCU1 (1XU1).

a If there is no ground signal:

Repair the wiring between:
* Pin AA/8A of GCU1 (1XU1) and the ground
* Pin AA/2E of GCU1 (1XU1) and the ground
* Pin AA/4G of GCU1 (1XU1) and the ground.

Install GCU1 AMM 24-22-34-400-001.

2 On the rack connector of GCU1 (1XU1), do a visual inspection of these pins:

Pin AA/3E of GCU1 (1XU1)
Pin AA/5E of GCU1 (1XU1)
Pin AA/5A of GCU1 (1XU1).

a If these pins are connected, do a check for a short to ground at:

Pin AA/3E of GCU1 (1XU1)
Pin AA/5E of GCU1 (1XU1)
Pin AA/5A of GCU1 (1XU1).

* If there is a short to ground:
* - Repair it.
* - Install GCU1 AMM 24-22-34-400-001.

3 On the rack connector of GCU1 (1XU1), do a visual inspection of this pin:

Pin AA/7C of GCU1 (1XU1).

a If this pin is connected:
* - Repair it.
* - Install GCU1 AMM 24-22-34-400-001.
(b) If the BITE test gives the maintenance message TEST PASSED:

Stop the trouble shooting procedure.

Subtask 24-00-00-810-070-E ** ON A/C NOT FOR ALL

A. If the TSD GCU is NOT AVAIL or if the TSD GCU is AVAIL but the TSD 113 OF3_TRIP fault code is not shown:

Replace GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

(1) If the fault continues:

Do an operational test of the GAPCU with the CFDS AMM 24-41-00-740-002.

(a) If the BITE test gives the maintenance message TEST FAILED:

Remove GCU1 AMM 24-22-34-000-001.

1 Do a check for a ground signal at ASM 242202:

Pin AA/5A of GCU1 (1XU1)
Pin AA/3E of GCU1 (1XU1)
Pin AA/4G of GCU1 (1XU1).

a If there is no ground signal:

Repair the wiring between:
* Pin AA/5A of GCU1 (1XU1) and the ground
* Pin AA/3E of GCU1 (1XU1) and the ground
* Pin AA/4G of GCU1 (1XU1) and the ground.

Install GCU1 AMM 24-22-34-400-001.

2 On the rack connector of GCU1 (1XU1), do a visual inspection of these pins:

Pin AA/5E of GCU1 (1XU1)
Pin AA/2E of GCU1 (1XU1)
Pin AA/8A of GCU1 (1XU1).

a If these pins are connected, do a check for a short to ground at:

Pin AA/5E of GCU1 (1XU1)
Pin AA/2E of GCU1 (1XU1)
Pin AA/8A of GCU1 (1XU1).

* If there is a short to ground:
* - Repair it.
* - Install GCU1 AMM 24-22-34-400-001.

3 On the rack connector of GCU1 (1XU1), do a visual inspection of this pin:

Pin AA/7C of GCU1 (1XU1).

a If this pin is connected:
* - Repair it.
* - Install GCU1 AMM 24-22-34-400-001.
(b) If the BITE test gives the maintenance message TEST PASSED:

Stop the trouble shooting procedure.

Subtask 24-00-00-810-092-A ** ON A/C NOT FOR ALL

B. If, on the lower ECAM DU, the GEN1 parameters are correct and the load is different from 0%:

Replace the GLC-1 [9XU1] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

(1) If the fault continues:

Replace the SDAC-1 [1WV1] and/or SDAC-2 [1WV2] AMM 31-55-34-000-001 and AMM 31-55-34-400-001.

(2) If the fault continues:

Do a check and repair the wiring ASM 242202 between:
. Pin AA/5A of the SDAC-1 and pin B/33 of the GLC-1
. Pin AA/5A of the SDAC-2 and pin B/33 of the GLC-1
. Pin B/31 of the GLC-1 and the ground.

Subtask 24-00-00-810-092-B ** ON A/C NOT FOR ALL

B. If, the GEN 1 FAULT warning message is present, the GEN1 parameters are correct and the load is different from zero percent:

Replace the GLC-1 [9XU1] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

(1) If the fault continues:

Replace the SDAC-1 [1WV1] and/or SDAC-2 [1WV2] AMM 31-55-34-000-001 and AMM 31-55-34-400-001.

(2) If the fault continues:

Do a check and repair the wiring ASM 242202 between:
. Pin AA/5A of the SDAC-1 and pin B/33 of the GLC-1
. Pin AA/5A of the SDAC-2 and pin B/33 of the GLC-1
. Pin B/31 of the GLC-1 and the ground.

Subtask 24-00-00-810-094-B ** ON A/C NOT FOR ALL

C. If the TSD GCU is AVAIL and if there is the TSD 113 OF3_TRIP fault code is shown:
(1) Do a check for insulation and continuity of the PMG wiring ASM 242201 between pins A/C 9/10/11 of the GCU 1 (1XU1) and pins A 11/2/10 of the IDG 1 (4000XU).
(a) If the wiring is correct:

Replace IDG-ENG 1 [4000XU1] AMM 24-21-51-000-803 and AMM 24-21-51-400-803.

(b) If the wiring is not correct, repair or replace as necessary.
(c) If the fault continues:

Replace GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

Subtask 24-00-00-810-094-H ** ON A/C NOT FOR ALL

C. If the TSD GCU is AVAIL and if there is the TSD 113 OF3_TRIP fault code is shown:
(1) Do a check for insulation and continuity of the PMG wiring ASM 242201 between pins A/C 9/10/11 of the GCU 1 (1XU1) and pins B 14/12/13 of the IDG 1 (4000XU).
(a) If the wiring is correct:

Replace the IDG [4000XU] AMM 24-21-51-000-040 and AMM 24-21-51-400-040.

(b) If the wiring is not correct, repair or replace as necessary.
(c) If the fault continues:

Replace the GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

Subtask 24-00-00-710-061-A

D. When you replace a component or repair the wiring:

do the subsequent flight before you do the check to make sure that the problem related to this fault symptom is repaired.
If the upper ECAM DU gives the GEN 1 FAULT warning, continue the trouble shooting.

5. Close-up
Subtask 24-00-00-860-056-A

A. Put the aircraft back to its initial configuration.
(1) Do the EIS stop procedure
AMM 31-60-00-860-002.
(2) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
(3) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:26:08 UTC