---
title: CarKeyErrorCode.FunctionUnknown
framework: CarKey
role: symbol
role_heading: Case
platforms: [iOS 16.0+, iPadOS 16.0+, Mac Catalyst 16.0+, macOS 13.3+, watchOS 9.0+]
path: carkey/carkeyerrorcode/functionunknown
---

# CarKeyErrorCode.FunctionUnknown

An error that indicates the vehicle didn’t recognize the specified function identifier.

## Declaration

```swift
case FunctionUnknown
```

## Discussion

Discussion Verify that the integer value in your FunctionIdentifier type matches one your vehicle supports.

## See Also

### Getting the Error Code

- [CarKeyErrorCode.AnotherRequestInProgress](carkey/carkeyerrorcode/anotherrequestinprogress.md)
- [CarKeyErrorCode.ClientInBackground](carkey/carkeyerrorcode/clientinbackground.md)
- [CarKeyErrorCode.EnduringRequestUsingEventMethod](carkey/carkeyerrorcode/enduringrequestusingeventmethod.md)
- [CarKeyErrorCode.FeatureNotSupported](carkey/carkeyerrorcode/featurenotsupported.md)
- [CarKeyErrorCode.Internal](carkey/carkeyerrorcode/internal.md)
- [CarKeyErrorCode.MessageTooLong](carkey/carkeyerrorcode/messagetoolong.md)
- [CarKeyErrorCode.RequestNotInProgress](carkey/carkeyerrorcode/requestnotinprogress.md)
- [CarKeyErrorCode.RequestTimedOut](carkey/carkeyerrorcode/requesttimedout.md)
- [CarKeyErrorCode.SecurityViolation](carkey/carkeyerrorcode/securityviolation.md)
- [CarKeyErrorCode.SessionNotActive](carkey/carkeyerrorcode/sessionnotactive.md)
- [CarKeyErrorCode.VehicleNotConnected](carkey/carkeyerrorcode/vehiclenotconnected.md)
- [CarKeyErrorCode.VehicleNotFound](carkey/carkeyerrorcode/vehiclenotfound.md)