04/08/21
Message Overview:
Message Description:
Auxiliary Power Unit (APU) Electronic Control Unit (ECU) is reporting an open or short circuit of the Surge Valve (SCV) solenoid.
Possible Causes:
- Surge Control Solenoid (V10)
- Auxiliary Power Unit (APU) Electronic Control Unit (ECU) (A39)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Surge Valve | AMM 49-51-01-000-801 |
| Installation of the Surge Valve | AMM 49-51-01-400-801 |
| Removal of the Auxiliary Power Unit (APU) Electronic Control Unit (ECU) | AMM 49-61-01-000-801 |
| Installation of the Auxiliary Power Unit (APU) Electronic Control Unit (ECU) | AMM 49-61-01-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Do wiring check from APU ECU (A39) to the Surge Valve (V10) for the following wires:
From To Result Conn. A39BP1-2C Conn. V10P1-1 Conn. A39BP1-2D Conn. V10P1-2 - If the check is satisfactory, continue with next step.
- If the check is not satisfactory, repair defective wiring.
- Replace the Surge Valve (V10). Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Replace APU ECU (A39).
- Do close out.