06/30/21
Message Overview:
Message Name:
CBW MECHANICALLY FAILED OPEN WITH CLOSED POSITION INDICATION ON EICAS
| Message Code: | 301OBS006 |
| Effectivity: | All |
| System: | Wing Cross Bleed Valve |
| System Description: | 36-11-00 |
| Schematic Diagram: | 36-11-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 30-11-03 [ Global Express ] [ G5000 ] [ Global XRS ] |
Message Description:
The Wing Cross Bleed Valve (or Wing Anti-Ice (WAI) Isolation Valve) mechanically failed open with a closed position indication on the Engine Indication and Crew Alerting System (EICAS).
Possible Causes:
- Wing Cross Bleed Valve (CBW) (L33)
- Left Bleed Management Controller (A69)
- Right Bleed Management Controller (A70)
- Junction Box (JB3)/PCB4
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter:
- When CBW is fully closed, CBW L33P1-5 provides a ground signal (CBW L33 pins 6 and 5 are shorted) to BMCs
- When CBW is fully open, CBW L33P1-1 provides a ground signal (CBW L33 pins 6 and 1 are shorted) to BMCs
- CBW L33 pin 6 is connected to Ground Stud GS390 to provide the ground signal for fully closed/fully open to BMCs
Quick Links:
| Removal of the Junction Box JB3 | AMM 24-00-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Junction Box JB3 | AMM 24-00-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Junction Box JB3 Circuit-Cards |
AMM 24-00-02-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Junction Box JB3 Circuit-Cards |
AMM 24-00-02-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Operational Test of the WING XBLEEDM System |
AMM 30-11-00-710-802 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Wing Cross-Bleed Valve | AMM 30-11-09-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Wing Cross-Bleed Valve | AMM 30-11-09-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Bleed Management Controller | AMM 36-11-33-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Bleed Management Controller | AMM 36-11-33-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Manually close CBW.
- If CBW cannot be closed, go to step 3.
- If CBW closed and EICAS show fully closed, continue with next step.
- Perform a CBW operational test.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace CBW.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Perform wiring checks between BMC 1, BMC 2, JB3, CBW and GS390.
- If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
NOTE: Remove all interface components for short test.
- Replace BMC 1.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace BMC 2.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PCB4/JB3.
- Do close out.