<!--
{
  "availability" : [
    "iOS: 16.0.0 -",
    "iPadOS: 16.0.0 -",
    "macCatalyst: 16.0.0 -",
    "macOS: 13.3.0 -",
    "watchOS: 9.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CarKey",
  "identifier" : "/documentation/CarKey/VehicleReport/proprietaryData(for:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "CarKey"
    ],
    "preciseIdentifier" : "s:6CarKey13VehicleReportV15proprietaryData3for10Foundation0F0VSgAA18FunctionIdentifierV_tKF"
  },
  "title" : "proprietaryData(for:)"
}
-->

# proprietaryData(for:)

Retrieves the proprietary data associated with one of the
vehicle’s functions.

```
func proprietaryData(for function: FunctionIdentifier) throws -> Data?
```

## Parameters

`function`

The function identifier for the given vehicle
feature. If you specify an unknown feature, this method throws
an error. For a list of the vehicle’s supported features,
see the [`supportedFunctions`](/documentation/CarKey/VehicleReport/supportedFunctions) property.

## Return Value

A data object, or `nil` if no data was present for
the specified feature.

## Discussion

When it receives new data from a vehicle, the system updates
the vehicle report and notifies the session delegate. Call
this method to retrieve any data associated with a particular
feature of your vehicle.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)