diff --git a/docs/energy_local_control.md b/docs/energy_local_control.md
index b172187..3332aac 100644
--- a/docs/energy_local_control.md
+++ b/docs/energy_local_control.md
@@ -200,6 +200,10 @@ a genuinely empty client list. Catch `InvalidResponse` (or
 will not catch it. Either way, a `null` response here tells you nothing
 about whether the key actually works.
 
+Any 502 response, including one from a gateway-relay command endpoint, raises
+`tesla_fleet_api.exceptions.BadGateway` regardless of whether the response
+carries a JSON body.
+
 To revoke a key, call `remove_authorized_client(public_key)` with its DER bytes
 or the base64 string returned by `list_authorized_clients()`. Removal does not
 require physical presence proof: any paired key can revoke every other key,
diff --git a/tesla_fleet_api/exceptions.py b/tesla_fleet_api/exceptions.py
index e9a478f..acc62e6 100644
--- a/tesla_fleet_api/exceptions.py
+++ b/tesla_fleet_api/exceptions.py
@@ -381,6 +381,16 @@ class InternalServerError(TeslaFleetError):
     status = 500
 
 
+class BadGateway(TeslaFleetError):
+    """The server, acting as a gateway, received an invalid response from an upstream server."""
+
+    message = (
+        "The server, acting as a gateway, received an invalid response from an "
+        "upstream server."
+    )
+    status = 502
+
+
 class ServiceUnavailable(TeslaFleetError):
     """Either an internal service or a vehicle did not respond (timeout)."""
 
@@ -1368,6 +1378,8 @@ async def raise_for_status(resp: aiohttp.ClientResponse) -> None:
         raise ClientClosedRequest(data)
     elif resp.status == 500:
         raise InternalServerError(data)
+    elif resp.status == 502:
+        raise BadGateway(data)
     elif resp.status == 503:
         raise ServiceUnavailable(data)
     elif resp.status == 504:
diff --git a/tests/test_bad_gateway_classification.py b/tests/test_bad_gateway_classification.py
new file mode 100644
index 0000000..9aefc2c
--- /dev/null
+++ b/tests/test_bad_gateway_classification.py
@@ -0,0 +1,96 @@
+"""502 classification: always a TeslaFleetError, regardless of body shape.
+
+A 502 must always become a ``TeslaFleetError`` subclass instead of leaking a
+raw ``aiohttp.ClientResponseError`` - see
+``tesla_fleet_api.exceptions.raise_for_status``.
+"""
+
+from contextlib import asynccontextmanager
+from unittest import IsolatedAsyncioTestCase
+from unittest.mock import AsyncMock, MagicMock
+
+from yarl import URL
+
+from tesla_fleet_api.const import Method
+from tesla_fleet_api.exceptions import BadGateway
+from tesla_fleet_api.tesla.fleet import TeslaFleetApi
+
+
+class _RequestTestApi(TeslaFleetApi):
+    """Expose the protected _request for testing."""
+
+    async def request(
+        self,
+        method: Method,
+        path: str,
+        params: dict[str, object] | None = None,
+        json: dict[str, object] | None = {},
+    ) -> dict[str, object]:
+        return await self._request(method, path, params=params, json=json)
+
+
+def _make_api(*, response: object) -> _RequestTestApi:
+    session = MagicMock()
+
+    @asynccontextmanager
+    async def _ctx(*args, **kwargs):
+        yield response
+
+    session.request = MagicMock(side_effect=lambda *a, **k: _ctx(*a, **k))
+    return _RequestTestApi(
+        session=session,
+        access_token="access-token",
+        server="https://fleet.example.com",
+    )
+
+
+def _fake_response(
+    *,
+    path: str,
+    content_type: str = "application/json",
+    json_body: object = None,
+    text_body: str = "",
+):
+    resp = MagicMock()
+    resp.status = 502
+    resp.ok = False
+    resp.content_type = content_type
+    resp.url = URL(f"https://fleet.example.com{path}")
+    resp.headers = {}
+    resp.json = AsyncMock(return_value=json_body if json_body is not None else {})
+    resp.text = AsyncMock(return_value=text_body)
+    return resp
+
+
+class BadGatewayClassificationTests(IsolatedAsyncioTestCase):
+    async def test_json_bodied_502_raises_bad_gateway(self) -> None:
+        resp = _fake_response(
+            path="/api/1/energy_sites/123/command/add_authorized_client",
+            json_body={"error": "gateway unreachable"},
+        )
+        api = _make_api(response=resp)
+        with self.assertRaises(BadGateway):
+            await api.request(
+                Method.POST, "api/1/energy_sites/123/command/add_authorized_client"
+            )
+
+    async def test_bodyless_502_raises_bad_gateway(self) -> None:
+        resp = _fake_response(
+            path="/api/1/energy_sites/123/command/authorized_clients",
+            content_type="text/plain",
+            text_body="",
+        )
+        api = _make_api(response=resp)
+        with self.assertRaises(BadGateway):
+            await api.request(
+                Method.GET, "api/1/energy_sites/123/command/authorized_clients"
+            )
+
+    async def test_non_gateway_endpoint_502_also_raises_bad_gateway(self) -> None:
+        resp = _fake_response(
+            path="/api/1/vehicles/123/vehicle_data",
+            json_body={"error": "upstream error"},
+        )
+        api = _make_api(response=resp)
+        with self.assertRaises(BadGateway):
+            await api.request(Method.GET, "api/1/vehicles/123/vehicle_data")