AWS IoT FleetWise will no longer be open to new customers as of April 30, 2026. Existing AWS IoT FleetWise customers can continue using the service. The [Guidance for Connected Mobility on AWS](https://aws.amazon.com/solutions/guidance/connected-mobility-on-aws/) provides guidance on how to develop and deploy modular services for connected mobility solutions that can be used to achieve equivalent capabilities as AWS IoT FleetWise.

# Create a data collection campaign for diagnostic trouble codes
<a name="dtc-data-collection"></a>

**Important**  
Access to certain AWS IoT FleetWise features is currently gated. For more information, see [AWS Region and feature availability in AWS IoT FleetWise](fleetwise-regions.md).

This topic describes how to create a data collection campaign for diagnostic trouble codes (DTC).

1. Define a custom signal on the Edge. You need to define the decoding rules for the DTC signal on the Edge as a custom decoded signal. For more information, see [Tutorial: Configure network agnostic data collection using a custom decoding interface](network-agnostic-data-collection.md).

1. Define custom function on the Edge. You need to define a custom function for collecting DTC signals on the Edge at a compiled time.

   For more information, see the [custom function guide](https://github.com/aws/aws-iot-fleetwise-edge/blob/main/docs/dev-guide/custom-function-dev-guide.md ) and the [DTC data collection reference implementation](https://github.com/aws/aws-iot-fleetwise-edge/blob/main/docs/dev-guide/edge-agent-uds-dtc-dev-guide.md#dtc_query-function-implementation) in the *Edge Agent Developer Guide*.
**Note**  
An example custom defined function is `DTC_QUERY` as shown in the [demo script](https://github.com/aws/aws-iot-fleetwise-edge/blob/main/docs/dev-guide/edge-agent-uds-dtc-dev-guide.md).

1. Create a signal catalog that models a DTC signal as a string type.

   ```
   [
    {
       "branch": {
           "fullyQualifiedName": "Vehicle",
           "description": "Vehicle"
           }
         },
         {
       "branch": {
           "fullyQualifiedName": "Vehicle.ECU1",
           "description": "Vehicle.ECU1"
           }
         },
         {
       "sensor": {
           "fullyQualifiedName": "Vehicle.ECU1.DTC_INFO",
           "description": "Vehicle.ECU1.DTC_INFO",
           "dataType": "STRING"
         }
      }
    ]
   ```

1. Create and activate a vehicle model with the DTC signal added.

1. Create and activate a decoder manifest with the DTC signal added. The DTC signal should be a `CUSTOM_DECODING_SIGNAL` signal decoder type with a `CUSTOM_DECODING_INTERFACE` network interface type.  
**Example signal decoder**  

   ```
   [
     {
       "fullyQualifiedName": "Vehicle.ECU1.DTC_INFO",
       "interfaceId": "UDS_DTC",
       "type": "CUSTOM_DECODING_SIGNAL",
       "customDecodingSignal": {
         "id": "Vehicle.ECU1.DTC_INFO"
       }
     }
    ]
   ```  
**Example network interface**  

   ```
   [
     {
       "interfaceId": "UDS_DTC",
       "type": "CUSTOM_DECODING_INTERFACE",
       "customDecodingInterface": {
         "name": "NamedSignalInterface"
       }
     }
   ]
   ```
**Note**  
Controller Area Network (CAN) signals don't support the string data type.

1. Provision and create vehicles. The vehicles must utilize a vehicle model (model manifest) and decoder manifest that were activated in the previous steps.

1. Create and approve the campaign. You need to create a campaign by defining DTC signals (optionally with telemetry signals) and deploy it to vehicles.

1. Access the data in the defined destination. DTC data includes the `DTCCode`, `DTCSnapshot`, and `DTCExtendedDatastrings` as a raw string in the data destination defined in the campaign.