> ## Documentation Index
> Fetch the complete documentation index at: https://docs.telemax.com.au/llms.txt
> Use this file to discover all available pages before exploring further.

# DTC codes

> Enriched diagnostic trouble codes for a vehicle with AI analysis and detection location.

### Overview

Returns DTC (Diagnostic Trouble Code) records from the most recent engine fault event for a vehicle. V2 returns enriched data including AI-generated descriptions, possible causes, recommended actions, severity, and the location where the fault was detected.

<Warning>This route (`/dtc`) is not deployed in staging — all requests return `PATH_NOT_FOUND`. Use [`GET /v2/api/vehicles/{id}/engine-codes`](/v2/api-reference/get-vehicles-id-engine-codes) instead, which is the active V2 replacement for this endpoint.</Warning>

<Note>The V1 version of this endpoint is [DTC codes](/v1/api-reference/get-devices-dtc-codes). V2 is paginated and significantly enriched.</Note>

<Note>**Rate limit:** 10 req/s · 30/min · 6,000/hr · 144,000/day</Note>

### Endpoint

`GET /v2/api/vehicles/{id}/dtc`

### Path parameters

<ParamField path="id" type="integer" required>
  Vehicle ID.
</ParamField>

### Query parameters

<ParamField query="page" type="integer" default="1">
  Page number (1-based).
</ParamField>

<ParamField query="pageSize" type="integer" default="50">
  Records per page.
</ParamField>

### Response

**200 OK** — `PagedListResult<DtcDto>`

| Field               | Type             | Description                                                                           |
| ------------------- | ---------------- | ------------------------------------------------------------------------------------- |
| code                | string           | Raw DTC code (e.g. `P0420`)                                                           |
| description         | string           | Code description                                                                      |
| whyThisMatters      | string\[]        | Impact on vehicle operation                                                           |
| possibleCauses      | string\[]        | Likely root causes                                                                    |
| recommendedActions  | string\[]        | Suggested remediation steps                                                           |
| severity            | string \| null   | Urgency level (e.g. `"High"`, `"Medium"`, `"Low"`); may be null for older cached data |
| detectedAt          | datetime \| null | When the fault was detected (user's timezone)                                         |
| detectedAtFormatted | string           | Formatted detection timestamp                                                         |
| location.address    | string \| null   | Street address where the fault was detected (null if geocoding failed)                |
| location.latitude   | number \| null   | Latitude of detection                                                                 |
| location.longitude  | number \| null   | Longitude of detection                                                                |

### Example response

```json theme={null}
{
  "items": [
    {
      "code": "P0420",
      "description": "Catalyst System Efficiency Below Threshold (Bank 1)",
      "whyThisMatters": ["Reduced emissions control", "Potential fuel efficiency loss"],
      "possibleCauses": ["Worn catalytic converter", "Faulty O2 sensor"],
      "recommendedActions": ["Inspect catalytic converter", "Check oxygen sensors"],
      "severity": "Medium",
      "detectedAt": "2026-04-27T14:30:00",
      "detectedAtFormatted": "27 Apr 2026 2:30 PM",
      "location": {
        "address": "42 George St, Sydney NSW 2000",
        "latitude": -33.8688,
        "longitude": 151.2093
      }
    }
  ],
  "currentPage": 1,
  "numberOfPages": 1,
  "totalResults": 1,
  "lastResultIndex": 0
}
```

### Error responses

| Status | Meaning                                    |
| ------ | ------------------------------------------ |
| 401    | Token does not have access to this vehicle |
| 404    | Vehicle not found                          |

```bash theme={null}
curl "https://api.telemax.com.au/v2/api/vehicles/88421/dtc" \
  -H "Authorization: Bearer <token>"
```