04/09/21
Message Overview:
Message Description:
Proximity Sensor Electronic Unit (PSEU) detects an internal SHORT in the Proximity Sensor PX49, Right-hand Over-Wing Emergency Door Locked or the wiring to the proximity sensor is shorted to the aircraft.
Possible Causes:
- Proximity Sensor Electronic Unit (PSEU) (A9)
- Right Overwing Emergency Door Closed 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 |
| Operational Test of the Door Sensors | AMM 52-71-00-710-801 |
| Built-In Test of the Door Proximity-Sensors | AMM 52-71-00-740-801 |
| Removal of the Over-Wing Emergency-Exit Proximity-Sensor | AMM 52-71-21-000-801 |
| Installation of the Over-Wing Emergency-Exit Proximity-Sensor | AMM 52-71-21-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | 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.
- Remove the PSEU from its rack and disconnect the splice SP124.
- Do wiring checks (shorted to ground = failure) between SP124 (pins A2, B2) and 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.
- Do close out.
