Fault Message:

ELECTROHYDRAULIC SERVO VALVE/WIRING

Fault Code:

3250010DWY

Associated CAS:

NOSE STEER FAIL
(Caution)

Associated SCU window fault code: E-17

Nose Wheel Steering Control Unit (SCU) has detected a failure with the Steering Manifold Electro-Hydraulic Servo Valve.

• Steering Manifold/Electro-Hydraulic Servo Valve (EHSV) (L12)
• Steering Control Unit (SCU) (A36)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-32-0280 - Nose Wheel Steering - Troubleshooting of SCU GW415-8100-3

Forum Articles/Infoservice/Newsletter: None

The Fault annunciation window in front of the Steering Control Unit (SCU) may be used to identify which part of the system is at fault. Refer to the CMM 32-50-19 Appendix 1, Fault code definition table.

1. Re-seat the SCU.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

2. Perform wiring checks between the SCU and the Steering manifold Electro-hydraulic servo valve (L12) using the table below:
   Table data was measured at 21-24 degree Celsius. See pinout image below:
   

   Name	From	To	Expected Result	Result
   Torque Motor Coils (Parallel)	A36P1-37	A36P1-38	465-535 Ohms
   Secondary Coil LVDT	A36P1-33	A36P1-34	73-85 Ohms
   Secondary Coils (Series Connection) LVDT	A36P1-32	A36P1-34	146-170 Ohms
   Secondary Coil LVDT	A36P1-32	A36P1-33	73-85 Ohms
   Primary Coil LVDT	A36P1-35	A36P1-36	71-83 Ohms

   1. If wiring checks are not good, repair defective wiring as required and do close out.
   2. If wiring checks are good, continue with next step.
      NOTE: While wiring checks are being accomplished have a second person “shake down” wiring along the top side of the actuators. Inspect wiring on Actuators carefully for extreme bends and kinks or breaks.

3. Replace the Steering Manifold.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

4. Perform the Rigging of the Nose Wheel Steering Control System.
5. Perform Rigging Check of the Steering Control System.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

6. Replace the SCU.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

7. Perform the Rigging of the Nose Wheel Steering Control System.
8. Perform Rigging Check of the Steering Control System.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

9. Perform the NVM download of the Steering Control Unit and contact the Bombardier Customer Response Center for help.
10. Do close out.