W DOC AIRBUS | TSM A320F

Failure of the Nose Wheel Steering Servo-Control or Incorrect Adjustment of the Nose Wheel Steering Gearbox

TASK 32-51-00-810-826-A
Failure of the Nose Wheel Steering Servo-Control or Incorrect Adjustment of the Nose Wheel Steering Gearbox

1. Possible Causes
  • SERVO CTL-N/W STEERING [6GC]
  • steering servo valve
  • BSCU [10GG]
  • wiring
  • SAFETY VALVE [2900GM]
  • nose-wheel steering servo-valve
  • RELAYS, HERMETICAL [62GA]
  • SAFETY VALVE-NLG DOOR CLOSING [2629GM]
  • LGCIU-1 [5GA1]
  • LGCIU-2 [5GA2]
  • SAFETY VALVE-L/G SYS ISOLATION [49GA]
  • [41GA]
  • Wiring
  • electro-distributor valve
  • connection of the hydraulic lines
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 12-14-32-614-004
Check NLG Shock Absorber Charge Pressure
AMM 32-22-00-010-001
Nose Gear Doors - Ground Doors Opening
AMM 32-22-00-410-001
Nose Gear Doors - Ground Doors Closing
ASM 323105
ASM 323107
AMM 32-31-17-000-001
Removal of the Landing Gear Safety-Valve
AMM 32-31-17-400-001
Installation of the Landing Gear Safety-Valve
AMM 32-31-19-000-001
Removal of the Safety Valves
AMM 32-31-19-400-001
Installation of the Safety Valves
AMM 32-31-34-000-001
Removal of the Landing-Gear (L/G) Door Selector Valve
AMM 32-31-34-400-001
Installation of the Landing-Gear (L/G) Door Selector Valve
AMM 32-31-71-000-001
Removal of the LGCIU
AMM 32-31-71-400-001
Installation of the LGCIU
ASM 324203
AMM 32-42-34-000-001
Removal of the Braking/Steering Control Unit (BSCU)
AMM 32-42-34-400-001
Installation of the Braking/Steering Control Unit (BSCU)
AMM 32-51-00-720-004
Functional Test of the Nose Wheel Steering with the Pedals
ASM 325101
AMM 32-51-19-220-001
Check of the Voltage at the Nose Wheel Steering Feedback Sensor
AMM 32-51-21-000-001
Removal of the Safety Valve
AMM 32-51-21-400-001
Installation of the Safety Valve
AMM 32-51-51-000-001
Removal of the Nose-Wheel Steering Servo-Control
AMM 32-51-51-000-002
Removal of the Nose Wheel Steering Servo-Valve
AMM 32-51-51-000-003
Removal of the Nose Wheel Steering Electro-Distributor
AMM 32-51-51-400-001
Installation of the Nose-Wheel Steering Servo-Control
AMM 32-51-51-400-002
Installation of the Nose Wheel Steering Servo-Valve
AMM 32-51-51-400-003
Installation of the Nose Wheel Steering Electro-Distributor
TSM TASK 32-42-00-03
NORMAL BRAKING - TASK SUPPORTING DATA
3. Fault Confirmation
Subtask 32-51-00-720-050-A
A. Test
   (1) Do the functional test of the steering of the nose wheels with the pedals AMM 32-51-00-720-004.
4. Fault Isolation
Subtask 32-51-00-810-091-B
A. If the test gives the maintenance message STEERING ELECTRO-HYD MODULE(6GC):
  • Do a check for water in the electrical connector of the N/W steering servo control (6GC) ASM 325101.
   (1) If there is water:
  • Examine the electrical connector for corrosion.
     (a) If there is corrosion:
     (b) If there is no corrosion:
  • Dry the electrical connector of the N/W steering servo control (6GC) and connect it.
   (2) If there is no water:
  • Remove the steering servo valve AMM 32-51-51-000-002
  • Do a check for water in the two electrical connectors of the N/W steering servo control.
     (a) If there is water:
  • Examine the electrical connectors for corrosion.
       1 If there is corrosion:
       2 If there is no corrosion:
     (b) If there is no water:
Subtask 32-51-00-810-099-C ** ON A/C NOT FOR ALL
B. If the fault continues, read the TROUBLE SHOOTING DATA of the BSCU 32-42-00-03 TSM TASK 32-42-00-03.
  • If the trouble shooting data gives the fault code 745: refer to paragraph C.
  • If the trouble shooting data gives the fault code 671: refer to paragraph D.
  • If the trouble shooting data gives the fault code 654: refer to paragraph E.
  • If the trouble shooting data gives the fault code 670: refer to paragraph F.

NOTE: If code XXX is shown after a free fall extension, no maintenance action is necessary.
Subtask 32-51-00-810-099-E ** ON A/C NOT FOR ALL
B. If the fault continues, read the TROUBLE SHOOTING DATA of the BSCU 32-42-00-03 TSM TASK 32-42-00-03.
  • If the trouble shooting data gives the fault code 745: refer to paragraph C.
  • If the trouble shooting data gives the fault code 671: refer to paragraph D.
  • If the trouble shooting data gives the fault code 670: refer to paragraph E.

NOTE: If code XXX is shown after a free fall extension, no maintenance action is necessary.
Subtask 32-51-00-810-079-C
C. If the fault continues and if the TROUBLE SHOOTING DATA gives the fault code 745:
   (1) If the fault continues:
     (a) If the fault continues:
  • Do a check and repair the wiring between the BSCU (10GG) pins AB/12E, 12F, 13E, 13F, 14E, 14F, 7G, 8G and the N/W steering servo control (6GC) pins A/G,H,E,F,C,D,A,B ASM 325101.
   (2) If the fault continues:
   (3) If the fault continues:
   (4) If the fault continues:
Subtask 32-51-00-810-081-D ** ON A/C NOT FOR ALL
D. If the fault continues and if the TROUBLE SHOOTING DATA gives the fault code 671:
   (1) If the fault continues:
   (2) If the fault continues:
  • Do a check and repair the wiring from the BSCU (10GG) pin AC/1F to Yellow pressure switch (3151GN) pin A/C, ASM 324203.
   (3) If the fault continues:
   (4) If the fault continues:
   (5) If the fault continues:
Subtask 32-51-00-810-081-G ** ON A/C NOT FOR ALL
D. If the fault continues and if the TROUBLE SHOOTING DATA gives the fault code 671:
   (1) If you can set the ground-door opening control lever to the closed position:
   (2) If you cannot set the ground-door opening control-lever to the closed position:
  • Do an LGCIU CB(s) reset.
     (a) If the fault continues:
  • Replace the RELAYS, HERMETICAL [62GA] .
     (b) If the fault continues:
     (c) If the fault continues:
     (d) If the fault continues:
     (e) If the fault continues:
     (f) If the fault continues:
     (g) If the fault continues:
  • Do a check and repair:
    . Wiring from the landing-gear system isolation-safety-valve (49GA) pin A/B to the hydraulic control relay (62GA) pin A/A2
    . Wiring from the landing-gear doors selector-valve (41GA) pins A/B, F to LGCIU1 pins AA/1A, 1B
    . Wiring from the hydraulic control relay (62GA) pin A/X1, to the ground-service bus-changeover relay (53GA) pin A/B2
    . Wiring from the hydraulic control relay (62GA) pin A/A1, to the ground-service bus-changeover relay (53GA) pin A/B2
    . Wiring from the hydraulic control relay (62GA) pin A/X2, to the hydraulic control relay (62GA) pin A/X1
    . Wiring from the hydraulic control relay (62GA) pin A/X2 to ADIRU1 (1FP1) pin AA/13H, to ADIRU3 (1FP3) pin AA/13H, to LGCIU1 (5GA1) pin AA/10K, ASM 323105 and ASM 323107
    . Wiring from the BSCU (10GG) pin AA/13F to the Green pressure switch (1151GN) pin A/C, ASM 324203.
   (3) If the fault continues:
   (4) If the fault continues:
   (5) If the fault continues:
Subtask 32-51-00-810-080-C ** ON A/C NOT FOR ALL
E. If the fault continues and if the TROUBLE SHOOTING DATA gives the fault code 654:
   (1) If the fault continues:
   (2) If the fault continues:
   (3) If the fault continues:
Subtask 32-51-00-810-080-D ** ON A/C NOT FOR ALL
DELETED
Subtask 32-51-00-810-114-C
F. If the fault continues and if the TROUBLE SHOOTING DATA gives the fault code 670:
  • Do a check of the resistance value between the pins A/A and A/B of the N/W steering servo-control (6GC) ASM 325101.
  • Make sure that the resistance value is between 450 and 550 ohms.
   (1) If the test is not ok:
   (2) If the test is ok:
     (a) If the fault continues:
  • Do a check and repair the wiring between the BSCU (10GG) pins AB/7G, 8G and the N/W steering servo-control (6GC) pins A/A, B ASM 325101.
Subtask 32-51-00-810-116-B
G. If the fault message STEERING ELECTRO-HYD MODULE (6GC) appears:
   (1) Do a check of the connection of the hydraulic lines of the swivel valve AMM 32-51-51-400-001.
     (a) If the hydraulic lines are not correctly connected, remove the HCU block (6GC) AMM 32-51-51-000-001 and send it to overhaul facility.
Subtask 32-51-00-720-051-A
H. Test
Do the test given in Para. 3.A.
[Rev.8 from Aug 2018] 2026.04.04 04:31:49 UTC
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