This code system http://hl7.org/fhir/device-operation-status-reason defines the following codes:

CodeDisplayDefinition
3::6728 Check air supplyChecking of ventilator air supply is necessary.
3::6678 Battery needs replacementAdvisory: Replace Battery (a full charge is now a too small fraction of the original capacity or this is not a rechargeable battery that is close to empty.)
3::462 CO2 failureFailure occurred in a CO2 measuring device
3::6708 Time adjustment checkAdvisory: Check time (system asks user to check the time)
3::694 Patient ID changeAdvisory: The ID of the patient connected to the device has changed
3::724 Infusion volume completeAdvisory: Infusion of the specified volume has been completed
3::120 UnpluggedA component (sensor, module) has become unplugged
3::132 InoperableDevice has become inoperable
3::410 Alarm limitAlarm limit exceeded
<status value="active"/><experimental value="false"/><date value="2020-12-28T16:55:11+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="The availability status reason of the device."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/device-operation-status-reason"/><content value="complete"/><concept><code value="3::6728"/><display value="Check air supply"/><definition value="Checking of ventilator air supply is necessary."/></concept><concept><code value="3::6678"/><display value="Battery needs replacement"/><definition value="Advisory: Replace Battery (a full charge is now a too small fraction of the original capacity or this is not a rechargeable battery that is close to empty.)"/></concept><concept><code value="3::462"/><display value="CO2 failure"/><definition value="Failure occurred in a CO2 measuring device"/></concept><concept><code value="3::6708"/><display value="Time adjustment check"/><definition value="Advisory: Check time (system asks user to check the time)"/></concept><concept><code value="3::694"/><display value="Patient ID change"/><definition value="Advisory: The ID of the patient connected to the device has changed"/></concept><concept><code value="3::724"/><display value="Infusion volume complete"/><definition value="Advisory: Infusion of the specified volume has been completed"/></concept><concept><code value="3::120"/><display value="Unplugged"/><definition value="A component (sensor, module) has become unplugged"/></concept><concept><code value="3::132"/><display value="Inoperable"/><definition value="Device has become inoperable"/></concept><concept><code value="3::410"/><display value="Alarm limit"/><definition value="Alarm limit exceeded"/></concept></CodeSystem>