04/09/21
Message Overview:
Message Description:
Proximity Sensor Electronic Unit (PSEU) detects an OPEN circuit within the Proximity Sensor PX18 Passenger Door Handle Locked or in the wiring to the Proximity Sensor or aircraft.
Possible Causes:
- Proximity Sensor Electronic Unit (PSEU) (A9)
- Passenger Door Handle Locked Proximity Sensor (PX18)
- 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 Passenger-Door Locked Proximity-Sensor | AMM 52-71-01-000-802 |
| Installation of the Passenger-Door Locked Proximity-Sensor | AMM 52-71-01-400-802 |
| 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.
- Do wiring checks between PSEU A9AP1 (pins 8C, 7C) and SP130 (pins A2, B2). Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PX18.
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.




