DCS Rear Door Error
Otis · GAA21750AK3 Service Tool
What does Rear Door Error mean?
A failure was detected in the Door Check Sequence (DCS) specifically related to the rear door at a reported level. This error indicates that the rear door's operation or its associated safety contacts did not pass the automated check, blocking the OTIS 2000 Controllers MCS120/MCS220 elevator.
Common Causes
- Rear door not opening or closing correctly due to obstruction or mechanical issue.
- Faulty rear door safety contacts (DW input) or their wiring.
- Misalignment of the door or its tracks preventing correct operation.
- Issues with the rear door operator.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Identify the specific level where the error occurred from the GAA21750AK3 service tool display.
- 2
Visually inspect the rear door path for any physical obstructions or damage to the door panels or tracks.
- 3
Verify the functionality and proper alignment of the rear door safety contacts and limit switches.
- 4
Check electrical continuity of the rear door safety circuit wiring from the controller to the door contacts.