If a cartridge-connected sensor fails a start-up check, self-test, or communication check, the sensor enters a fault state. While in this fault state, the sensor cannot detect gas and gas readings do not display, to prevent invalid or misleading data.

The affected sensor is marked with an ‘X’ on the display to indicate it has failed.

A low-urgency notification triggers to alert the user to the sensor fault.

The condition remains active until the issue is resolved (e.g., power cycling or replacing the cartridge) to ensure users are not presented with invalid, missing, or misleading gas data.