940
Field Current Feedback A/D Saturated
Otis · DSD 412 Elevator System
What does 940 mean?
This fault occurs when the Field Analog-to-Digital (A/D) converter reading remains saturated for more than 15 seconds, indicating an issue with the field current feedback circuit.
Common Causes
- Component problem with the Field Interface Board.
- Problem with the Ribbon Cable (J33) connecting components.
- Component problem with the Main Control Board.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Replace the Field Interface Board.
- 2
Replace the Ribbon Cable (J33).
- 3
If the fault is still present after these steps, replace the Main Control Board.
Verified technical data. Last updated: March 2026
Related Faults
Source: Otis DSD 412 Elevator System