03/15/21
Message Overview:
Message Description:
PSEU Discrete Output DOT16B, MLGWOW to Total Air Temperature Probe (A16) driver failed.
Possible Causes:
- Proximity-Sensor Electronic Unit (PSEU) (A9)
- Right Total Air Temperature (TAT) Probe (A16)
- 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 the Total Air Temperature (TAT) Probe | AMM 34-11-13-000-801 |
| Installation of the Total Air Temperature (TAT) Probe | AMM 34-11-13-400-801 |
| 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.
- Do wiring check between Left Secondary Power Center TAT WOW Relay K98 A37P3 pin 5 and PSEU A9AP1 pin 5H. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PSEU.
- Do close out.


