Fault Message:

APU FEED SOV ELECT PWR/WRG

Fault Code:

284461CPK

Associated CAS:

APU FUEL SOV
(Caution)

APU FEED VALVE LMS/WRG FAULT shows when the conditions that follow occur:

1. The Auxiliary Power Unit (APU) Fire Handle is pulled or the APU is off.
2. The APU Shutoff-Valve is open.
3. The Electrical Management System (EMS)/DC Power Center (DCPC) has a failure.

OR

1. The APU Fire Handle is not pulled and the APU is on.
2. The APU Shutoff-Valve is closed.
3. The EMS/DCPC has a failure.

• Auxiliary Power Unit (APU) Fire Shutoff-Valve (SOV) (L40)
• Junction Box (JB4)
• Junction Box (JB4)/PCB3
• Relay (K29)
• Auxiliary Power Unit (APU) Fire-Detection-and-Extinguishing (FIREX) Handle (A211)
• Fuel Management Quantity and Gauging Computer (FMQGC) (A47)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: The APU Feed Valve is powered to the closed position.

1. Access the APU Feed SOV and disconnect connector L40P1. Did the valve remain closed?

   1. If YES, suspect the valve or the valve actuator for failure and replace as required and do close out.
   2. If NO, continue with next step.

2. Disconnect JB4 connector JB4AP1. Perform a wiring check as follows:

   From	To	Result
   L40P1-B	Ground
   L40P1-D	Ground
   L40P1-B	L40P1-D

   1. If there is continuity, repair defective wiring as required and do close out
   2. If there is no continuity, continue with next step.

3. Perform a wiring check as follows:

   From	To	Result
   L40P1-B	JB4AP1-3C
   L40P1-D	JB4AP1-3D

   1. If there is no continuity, repair defective wiring as required and do close out.
   2. If there is continuity, continue with next step.

4. Perform a wiring check between the APU FIREX Handle and the FMQGC and make sure the handle is providing a ground to the FMQGC.
5. Replace relay K29 on PCB 3 of JB4. Is the fault still present?

   1. If NO, do close out.
   2. If YES, continue with next step.

6. Replace FMQGC.
7. Do close out.