03/16/21
Message Overview:
Message Description:
The BCU has detected a discrepancy with one or more discrete input from the PSEU. This code can result from a fault with the PSEU or a component of the PSEU system.
Possible Causes:
- Weight-On-Wheel (WOW) System 1 Sensor
- Gear Handle Sensor
- Uplock Sensor
- Proximity-Sensor Electronic Unit (PSEU) (A9)
- Brake Control Unit (BCU) (A67)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Brake Control Unit | AMM 32-43-01-000-801 |
| Installation of the Brake Control Unit | AMM 32-43-01-400-801 |
| 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 |
| Data Download from the Maintenance Diagnostic Computer (MDC) | AMM 45-45-01-970-802 |
| 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:
- Address any 'PROX SYS FAULT', 'WOW FAIL' or 'GEAR DISAGREE' CAS message first.
- If no 'PROX SYS FAULT', 'WOW FAIL' or 'GEAR DISAGREE' message are associated with this code, do the following:
- Do a wiring check per the following table:
From (PSEU) Pin To (BCU) Pin A9AP1 3J A67P1 14 A9AP1 3H A67P1 84 A9AP1 3G A67P1 81 A9AP1 5G A67P1 82 - If wiring is found serviceable, replace BCU.
- If fault continues, replace PSEU.
- Do a wiring check per the following table:
- Do close out.