What is the first step in the disarming procedure for an ETD?

The first step in the disarming procedure for an Explosive Train Detector (ETD) involves setting the HTD ID code. This step is crucial because it establishes the identification and communication parameters necessary for the ETD to function correctly. By setting the HTD ID code, the operator ensures the ETD system can accurately link with the locomotive and recognize its status.

Establishing the ID code is essential before proceeding with any other actions, such as checking battery levels or pressing communication buttons, as it lays the groundwork for the safe deactivation of the ETD system. Without this step, subsequent procedures may not properly interface with the system, leading to potential safety risks or operational delays.