AFT FUEL XFER OFF
(Status)

AFT FUEL XFER OFF (status) shows when the AFT XFER switch on the FUEL control panel is set to OFF.

This troubleshooting applies when it is not under normal conditions.

NOTE: This troubleshooting sheet does not apply to the Global 5000.

• AFT XFER Switch (S2)
• Fuel Management and Quantity Gauging Computer (FMQGC)
• Ground Stud (GS884)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: The AFT FUEL XFER OFF (Status) CAS message does not display when AFT XFER knob is in the OFF position.

1. Turn on aircraft power and access the CAIMS PMAT

   • Access CAIMS.
   • Select System Diagnostics.
   • Select 28-00 FUEL.
   • Select Computer (FMQGC CH A(B).
   • Select LRU TEST
   • Select Cockpit fuel panel data CH A(B)

2. On the fuel control panel rotate the AFT TRANSFER KNOB to OFF.
3. Does the PMAT show the Manual Transfer OFF: go to TRUE?

   1. If YES, then go to step 9.
   2. If NO, then continue with the next step.

4. Gain access and remove the FMQGC and inspect the tray, connectors and pins. Make sure connector A47DP1 pin E13 is not damaged, bent and is secured properly into place.

   1. If the check is good, continue with the next step.
   2. If the check is not good, rectify/replace as necessary.

5. Perform a wiring continuity check per table below:
   

   FROM	TO	EXPECTED RESULT	RESULT
   A47DP1 - E13	Airframe Ground	Continuity

   1. If the wiring check is good, then go to step 9.
   2. If the wiring check is not good, then continue with the next step.

6. Remove the Fuel control panel (AP5), and disconnect AP5P2.
7. Perform a wiring continuity check per the table below:
   

   SWITCH POSITION	FROM	TO	EXPECTED RESULT	RESULT
   OFF	AP5J2 - 46	AP5J2 - 25	Continuity
   OFF	AP5P2 - 25	Airframe ground	Continuity

   1. If there is no continuity between AP5J2 - 46 and AP5J2 - 25, then suspect the AFT XFER SWITCH (S2).
   2. If there is no ground on AP5P2 - 25, then repair or replace wiring going to GS884 or GS884.
   3. If the wiring checks are good, go to next step.

8. Perform the wiring continuity check per table below:
   

   FROM	TO	EXPECTED RESULT	RESULT
   AP5P2 - 46	A47DP1 - E13	Continuity

   1. If the wiring check is good, continue with next step.
   2. If the wiring check is not good, then repair or replace wiring between the FMQGC and the Fuel Control Panel (AP5).

9. Re-install or re-rack the FMQGC making sure it is fully and properly pushed into place. Is the fault still present?

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

10. Replace FMQGC.