Front Door Error

DCS Front Door Error

Otis · GAA21750AK3 Service Tool

What does Front Door Error mean?

A failure was detected in the Door Check Sequence (DCS) specifically related to the front door at a reported level (e.g., Level 01). This error indicates that the front door's operation or its associated safety contacts did not pass the automated check, blocking the OTIS 2000 Controllers MCS120/MCS220 elevator.

Common Causes

  • Front door not opening or closing correctly due to obstruction or mechanical issue.
  • Faulty front door safety contacts (DW input) or their wiring.
  • Misalignment of the door or its tracks preventing correct operation.
  • Issues with the front door operator.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Identify the specific level where the error occurred from the GAA21750AK3 service tool display (e.g., - 01 DW).

  2. 2

    Visually inspect the front door path for any physical obstructions or damage to the door panels or tracks.

  3. 3

    Verify the functionality and proper alignment of the front door safety contacts and limit switches.

  4. 4

    Check electrical continuity of the front door safety circuit wiring from the controller to the door contacts.

Browse all codes in this manual (15)
Verified technical data. Last updated: March 2026

Related Faults

Source: Otis GAA21750AK3 Service Tool