Legacy Model X reports Fleet Telemetry support but configure returns unsupported_firmware

[fanhaipeng0403]

Bug Report: Legacy Model X — unsupported_firmware on Fleet Telemetry Config Despite Valid fleet_telemetry_version

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Summary

A legacy Model X appears to meet all documented Fleet Telemetry prerequisites for Intel Atom Model S/X vehicles. However, POST /api/1/vehicles/fleet_telemetry_config consistently skips the VIN with unsupported_firmware, even when configuring a single basic field such as Location.

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Environment

Field	Value
Vehicle	Legacy Tesla Model X
VIN	5YJXCCE23MF******
Region	China
Firmware	2026.8.3
fleet_telemetry_version	1.1.0
safety_screen_streaming_toggle_enabled	true
vehicle_command_protocol_required	false
Auth	Valid Tesla account authorization
OAuth Scopes	vehicle_device_data, vehicle_location, vehicle_cmds, vehicle_charging_cmds, offline_access

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Fleet Status

POST /api/1/vehicles/fleet_status

{
  "response": {
    "key_paired_vins": [],
    "unpaired_vins": ["5YJXCCE23MF******"],
    "vehicle_info": {
      "5YJXCCE23MF******": {
        "firmware_version": "2026.8.3",
        "vehicle_command_protocol_required": false,
        "discounted_device_data": false,
        "fleet_telemetry_version": "1.1.0",
        "total_number_of_keys": null,
        "safety_screen_streaming_toggle_enabled": true
      }
    }
  }
}

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Current Config

GET /api/1/vehicles/{vin}/fleet_telemetry_config

{
  "response": {
    "synced": true,
    "config": null,
    "limit_reached": false,
    "key_paired": false
  }
}

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Reproduction Steps

The following configurations were all attempted independently — all return the same error:

1. Full production telemetry config
2. Reduced config (excluding MilesSinceReset and SelfDrivingMilesSinceReset)
3. Minimal journey config: Gear, VehicleSpeed, Location, GpsHeading, Odometer
4. Single-field configs: Location, Odometer, VehicleSpeed

Response for all attempts:

POST /api/1/vehicles/fleet_telemetry_config

{
  "response": {
    "updated_vehicles": 0,
    "skipped_vehicles": {
      "missing_key": [],
      "unsupported_hardware": [],
      "unsupported_firmware": ["5YJXCCE23MF******"],
      "max_configs": []
    }
  }
}

After each attempt, GET /fleet_telemetry_config still returns "config": null.

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Telemetry Errors

GET /api/1/vehicles/{vin}/fleet_telemetry_errors

{
  "response": {
    "fleet_telemetry_errors": []
  }
}

No errors recorded on the vehicle side.

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Questions

1. Is unsupported_firmware expected for some legacy Model X vehicles even when fleet_status reports a non-empty fleet_telemetry_version and safety_screen_streaming_toggle_enabled: true?

2. If so, is there another fleet_status field that should be used to reliably determine whether a vehicle is actually configurable for Fleet Telemetry?

3. If not, could this be a backend eligibility issue specific to this VIN/firmware combination?

Happy to provide the full VIN privately to Tesla maintainers if needed.