Sudden Steering Swerve or Uncommanded Movement of the Steering

TASK 32-51-00-810-836-A
Sudden Steering Swerve or Uncommanded Movement of the Steering

1. Possible Causes

SERVO CTL-N/W STEERING [6GC]
SENSOR-N/W STRG FDBK,CTL CHAN [3GC]
SENSOR-N/W STRG FDBK,MONITORING CHAN [4GC]
wiring from the BSCU (10GG) to the feedback sensor (3GC)
wiring from the BSCU (10GG) to the N/W steering servo control (6GC)
wiring from the BSCU (10GG) to the feedback sensor (4GC)
BSCU [10GG]
wiring from the BSCU (10GG) to the N/W steering selector valve (6GC)
SEL VALVE/MANIFOLD ASSY [7GC]
wiring from the BSCU (10GG) to the N/W steering selector valve (7GC)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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 32-46-00-720-802	Functional Preland Test of the Normal/Alternate Braking and Steering Systems on the Ground
ASM 325101
AMM 32-51-19-000-001	Removal of the Nose Wheel Steering Feedback Sensor P/N C24763000
AMM 32-51-19-400-001	Installation of the Nose Wheel Steering Feedback Sensor P/N C24763000
AMM 32-51-23-000-001	Removal of the Selector Valve and Manifold-Assembly
AMM 32-51-23-400-001	Installation of the Selector Valve and Manifold-Assembly
AMM 32-51-51-000-001	Removal of the Nose-Wheel Steering Servo-Control
AMM 32-51-51-400-001	Installation of the Nose-Wheel Steering Servo-Control

3. Fault Confirmation
Subtask 32-51-00-710-058-A

A. Test
If the fault occurs when steering is active, perform subtask 32-51-00-810-098.
If the fault occurs when steering is disconnected, perform subtask 32-51-00-810-118.

4. Fault Isolation
Subtask 32-51-00-810-098-B

A. If steering swerve occurs when steering is active:

do a check for water (or moisture) in the electrical connectors of:
. the N/W steering servo control (6GC)
. the N/W steering feedback sensor (control channel) (3GC)
. the N/W steering feedback sensor (monitoring channel) (4GC)

(1) If there is water:

examine the electrical connectors for corrosion

(a) If there is corrosion, replace the damaged component(s):

SERVO CTL-N/W STEERING [6GC] AMM 32-51-51-000-001 and AMM 32-51-51-400-001.
SENSOR-N/W STRG FDBK,CTL CHAN [3GC] AMM 32-51-19-000-001 and AMM 32-51-19-400-001
SENSOR-N/W STRG FDBK,MONITORING CHAN [4GC] AMM 32-51-19-000-001 and AMM 32-51-19-400-001

(b) If there is no corrosion:

for the connectors of the steering feedback sensors (3GC) and (4GC):
. dry the electrical connectors and connect them.
for the connector of the steering servo control (6GC):
. dry the electrical connector
. make sure that the heat-shrink sleeve of the electrical connector is in the correct condition
. connect the electrical connector to the steering servo control (6GC) and fold back the end of the heat-shrink sleeve on the connector.

(2) If there is no water:

do a check and repair the wiring from the BSCU (10GG) to the feedback sensor (3GC): pins AB/15E, 15F, 8E, 8F, 9E, 9F to pins A/A, B, C, D, E, F ASM 325101.

(a) If the fault continues:

do a check and repair the wiring from the BSCU (10GG) to the N/W steering servo control (6GC): pins AB/12E, 12F, 13E, 13F, 14E, 14F to pins A/G, H, E, F, C, D ASM 325101.

(b) If the fault continues:

do a check and repair the wiring from the BSCU (10GG) to the feedback sensor (4GC): pins AB/14E, 14F, 10E, 10F, 11F, 11E to pins A/A, B, C, D, E, F ASM 325101.

replace the SERVO CTL-N/W STEERING [6GC] AMM 32-51-51-000-001 and AMM 32-51-51-400-001.

(d) If the fault continues:

replace the BSCU [10GG] , AMM 32-42-34-000-001 and AMM 32-42-34-400-001

Subtask 32-51-00-810-118-A ** ON A/C NOT FOR ALL

B. If steering uncommanded movement occurs when steering is disconnected:

Do the functional preland test of the steering system AMM 32-46-00-720-802.

(1) If the test gives the maintenance message STEERING ELECTRO-HYD MODULE (6GC):

Replace the SERVO CTL-N/W STEERING [6GC] AMM 32-51-51-000-001 and AMM 32-51-51-400-001.

(2) If the test gives the maintenance message BSCU (10GG):

Do a check and repair the wiring from the BSCU (10GG) to the N/W steering selector valve (6GC): pin AB/12D to pin A/J and pin A/K to ground ASM 325101.

(a) If the fault continues:

Replace the BSCU [10GG] AMM 32-42-34-000-001 and AMM 32-42-34-400-001.

Subtask 32-51-00-810-118-B ** ON A/C NOT FOR ALL

B. If steering uncommanded movement occurs when steering is disconnected:

Do the functional preland test of the steering system AMM 32-46-00-720-802.

(1) If the test gives the maintenance message STEERING SELECTOR VALVE (7GC):

Replace the SEL VALVE/MANIFOLD ASSY [7GC] AMM 32-51-23-000-001 and AMM 32-51-23-400-001.

(2) If the test gives the maintenance message BSCU (10GG):

Do a check and repair the wiring from the BSCU (10GG) to the N/W steering selector valve (7GC): pins AB/12D, 13D to pins A/A, B ASM 325101.

(a) If the fault continues:

Replace the BSCU [10GG] AMM 32-42-34-000-001 and AMM 32-42-34-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:31:51 UTC