07/02/21
Message Overview:
Message Name:
CBV MECHANICALLY FAILED OPEN WITH AMBER INTERMEDIATE POSITION INDICATION ON EICAS
| Message Code: | 361OBS005 |
| Effectivity: | All |
| System: | Bleed Air System |
| System Description: | 36-11-00 |
| Schematic Diagram: | 36-11-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 30-11-04 [ Global Express ] [ G5000 ] [ Global XRS ] |
Message Description:
The Cross Bleed Valve mechanically failed open with an amber intermediate position (not fully closed or not fully open) indication on the Engine Indication and Crew Alerting System (EICAS).
Possible Causes:
- Cross Bleed Valve (L35)
- Junction Box (PCB3/JB4)
- Bleed Management Controller (BMC) 1 (A69)
- Bleed Management Controller (BMC) 2 (A70)
- Data Acquisition Unit (DAU) 4 (A31)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
- When CBV is fully closed, CBV L35P1-5 provides a ground signal (CBV L35 pins 6 and 5 are shorted) to BMCs
- When CBV is fully open, CBV L35P1-1 provides a ground signal (CBV L35 pins 6 and 1 are shorted) to BMCs
- CBV L35P1-6 is connected to Ground Stud GS423 to provide the ground signal for fully closed/fully open to BMCs
Quick Links:
| Removal of the Junction Box JB4 | AMM 24-00-05-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Junction Box JB4 | AMM 24-00-05-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Data Acquisition Units (DAU) | AMM 31-42-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Data Acquisition Units (DAU) | AMM 31-42-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Cross-Bleed Valve | AMM 36-11-29-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Cross-Bleed Valve | AMM 36-11-29-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Operational Test of the Cross-Bleed Valve | AMM 36-11-29-710-801 [ 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 CBV.
- If CBV cannot be closed, go to step 3.
- If CBV closed and EICAS show fully closed, continue with next step.
- Perform a CBV operational test.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace CBV.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Perform wiring checks between BMC 1, BMC 2, JB4, DAU 4, CBV and GS423.
- 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.
- Swap DAU 4 with DAU 2.
- If system checks are good, replace DAU 4 and do close out.
- If fault remains, continue with next step.
- 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 Junction Box JB4 (PCB3/JB4).
- Do close out.