ISO 21956:2019

This document provides human machine interface (HMI) design specifications for keyless ignition systems that use key code carrying device for passenger cars (including sport utility vehicles and light trucks) and commercial vehicles (including heavy trucks and buses), independent of vehicle propulsion system. HMI specifications for the electrical key functions include actuation in normal conditions, emergencies, low battery, and avoidance of inadvertent actuations, alerts and specific non-standard situations.