04/21/21
Message Overview:
Message Name:
TR UL STOW SWITCH 4
Message Code:
B3-305040
Associated CAS:
| Reporting LRU: | R TR UL STOW SW |
| System Description: | 78-30-00 |
| Schematic Diagram: | None |
| Wiring Diagram: | None |
Message Description:
Left engine thrust reverser upper left stow switch fault 4.
[MCID 1403]
TR upper left Stow Switch 4.
A fault was sensed in the TR upper left stow switch circuit. This fault is most possibly in the TR upper left stow switch.
Possible Causes:
- Thrust Reverser (TR) Upper Left Stow Switch
- Upper Left Stow Switch Striker Plate and/or Bracket
- Full Authority Digital Engine Control (FADEC) Electronic Control Unit A (ECU) (A41)
- Full Authority Digital Engine Control (FADEC) Electronic Control Unit B (ECU) (A43)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-000-801 |
| Installation of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-400-801 |
| Deactivation of the Thrust Reverser (For Maintenance) | AMM 78-30-00-040-801 |
| Activation of the Thrust Reverser (For Maintenance) | AMM 78-30-00-440-801 |
| Operational Test of the Thrust Reverser | AMM 78-30-00-710-801 |
| General Visual Inspection of the Thrust Reverser | AMM 78-30-00-210-802 |
| General Visual Inspection of the Thrust-Reverser Wiring Harness | AMM 78-33-00-210-801 |
| Removal of the Thrust-Reverser Door Stow-Switch | AMM 78-33-01-000-802 |
| Installation of the Thrust-Reverser Door Stow-Switch | AMM 78-33-01-400-802 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- MCID 1403 fault present, troubleshoot using the following steps for aircraft and engine fault isolation with reference to the Light Engine Maintenance Manual Subtask 72-00-00-810-237-A01.
