W DOC AIRBUS | TSM A320F

Failure of the ENG MASTER SW 1 Signal to the GCU 1

TASK 24-20-00-810-864-A
Failure of the ENG MASTER SW 1 Signal to the GCU 1

1. Possible Causes
  • GCU-1 [1XU1]
  • CTL SW-ENG/MASTER 1 [3KC]
  • wiring
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
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 24-41-00-740-002
Operational Check of the GAPCU via the CFDS
ASM 761201
3. Fault Confirmation
Subtask 24-20-00-740-064-B ** ON A/C NOT FOR ALL
A. Test
   (1) Do the BITE test of the GAPCU AMM 24-41-00-740-002.
     (a) If the BITE test gives the message TEST FAILED:
  • do the trouble shooting given in Para 4.A.
     (b) If the BITE test gives the message TEST PASSED:
  • do the trouble shooting given in Para 4.B.
4. Fault Isolation
Subtask 24-20-00-810-190-A ** ON A/C NOT FOR ALL
A. If the BITE test gives the message TEST FAILED:
  • push the line key adjacent to the TEST FAILED message.
   (1) If the maintenance message GCU1 (1XU1) comes into view:
Subtask 24-20-00-810-135-A ** ON A/C NOT FOR ALL
B. If the BITE test gives the message TEST PASSED:
  • do a check of the contact of the ENG/MASTER 1 control switch (3KC) for correct operation between pins 3A and 1A ASM 761201.
   (1) If the contact do not operate correctly:
  • replace the CTL SW-ENG/MASTER 1 [3KC] on the ENG panel 115VU.
   (2) If the contact operate correctly:
  • do a check of the fuel-cutoff status wiring ASM 242202 for an open circuit between pin 3A of the ENG/MASTER 1 control switch and pin A/8C of the GCU 1.
     (a) If there is no continuity:
  • repair or replace as necessary.
     (b) If there is continuity:
Subtask 24-20-00-740-065-A ** ON A/C NOT FOR ALL
C. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:26:16 UTC
"WTRUIB" 2025