03/15/21
Message Overview:
Message Description:
Right Overwing Emergency Door Locked Sensor PX49 signal conditioning failed.
Possible Causes:
- Proximity-Sensor Electronic Unit (PSEU) (A9)
- Over-Wing Emergency-Exit Proximity-Sensor(PX49)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Proximity-Sensor Electronic Unit (PSEU) | AMM 32-61-09-000-801 |
| Installation of the Proximity-Sensor Electronic Unit (PSEU) | AMM 32-61-09-400-801 |
| Functional Test of the Proximity-Sensor Electronic Unit (PSEU) | AMM 32-61-09-720-801 |
| Removal of Over-Wing Emergency Exit Proximity Sensor | AMM 52-71-21-000-801 |
| Installation of Over-Wing Emergency Exit Proximity Sensor | AMM 52-71-21-400-801 |
| Built-In Test of the Door Proximity-Sensors | AMM 52-71-00-740-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Wire Repair | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Pull and reset the PSEU gear system breakers (CB1-C13, CB1-C14), (CB2-C13, CB2-C14).
- If system checks are good, do close out.
- If fault remains, continue with next step.
- If PX31, PX34, PX40, PX43 and PX46 also indicate Signal Conditioning Failure, troubleshoot these sensors for a short to ground. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PX49.
NOTE: Sensor resistance should be made with a meter using a < 10 mA supply of current. Never apply voltage through a sensor! Current will magnetize the sensor rendering it unreliable. Sensor resistance is typically 11 to 13 Ω.- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PSEU if failure is on PX49 only and the NVM download does not identify external inputs as the fault.
- Do close out.
