01/14/25
Message Overview:
Message Name:
CROSS BLEED VALVE WILL NOT OPEN
| Identifier: | 361OBS001 |
| Effectivity: | 20501-21399 |
| System: | Pneumatic |
| Associated CAS: | None |
| System Description: | 36-11-00 - Intermediate Pressure Bleed Air System |
| Schematic Diagram: | 36-11-00 - Intermediate Pressure Bleed Air System |
| Wiring Diagram: | 36-11-15 - Cross Bleed Valve |
Message Description:
When the Cross-bleed PBA is selected on the Air Cond/Bleed switch panel the Cross-bleed PBA dash does not illuminate indicating that the cross-bleed valve is open.
Possible Causes:
- K12 relay inside on JB2-DB1
- K13 relay inside on JB2-DB1
- XBLEED switch (SDS15)
- Cross Bleed Valve (CBV) (MPE2)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
Quick Links:
None
Troubleshooting Recommendations:
- Start an engine to see if the cross bleed valve OPENS.
- IF YES, then you can eliminate the Cross bleed valve (CBV) (MPE2) as a fault. Continue with the next step.
- IF NO, then the troubleshoot the associated MDC faults B3-008138 and B3-008139.
- Gain access to Junction Box 2.
- Ring-out DB1 board relays K12 and K13. Use the JB2 ring-out table HERE.
- If the relays check out good then suspect the PBA switch XBLEED (SDS15).