fix: end the heated seat and steering wheel commands with PARAMS_MAX

src/saic_ismart_client_ng/api/vehicle/climate/__init__.py

@@ -100,11 +100,11 @@ async def control_heated_seat(
     ) -> VehicleControlResp:
         """Set one heated seat, leaving the others alone.
 
-        Matches what the iSmart app sends (decrypted MG S6 EV traffic): request
-        type 5 with a single parameter for the chosen seat (17 front left,
-        18 front right, 25 rear left, 26 rear right) and no end-of-parameters
-        marker. Unlike ``control_heated_seats`` it doesn't have to re-send the
-        other front seat's level, and it can reach the rear seats.
+        Sends request type 5 with a single parameter for the chosen seat (17
+        front left, 18 front right, 25 rear left, 26 rear right), followed by
+        the end-of-parameters marker (255) like the other control commands.
+        Unlike ``control_heated_seats`` it doesn't have to re-send the other
+        front seat's level, and it can reach the rear seats.
 
         Front seats: 0 off, 1 low, 2 medium, 3 high. Rear seats are on/off
         only (in the app and in the car): send ``REAR_HEATED_SEAT_ON_LEVEL``
@@ -113,7 +113,10 @@ async def control_heated_seat(
         if not 0 <= level <= 3:
             msg = f"Heated seat level must be 0-3, got {level}"
             raise ValueError(msg)
-        rvc_params = [RvcParams(seat.value, level.to_bytes(1, "big"))]
+        rvc_params = [
+            RvcParams(seat.value, level.to_bytes(1, "big")),
+            RvcParams(RvcParamsId.PARAMS_MAX, b"\x00\x00\x00\x00"),
+        ]
         body = VehicleControlReq(
             rvc_req_type=RvcReqType.HEATED_SEATS,
             rvc_params=rvc_params,
@@ -126,17 +129,17 @@ async def control_heated_steering_wheel(
     ) -> VehicleControlResp:
         """Turn the heated steering wheel on or off.
 
-        Matches the traffic captured from the iSmart app on an MG S6 EV:
-        request type 8 with a single parameter, 24 = 1 (on) or 0 (off), and
-        no end-of-parameters marker. Other app builds or models may send
-        more than this; only the S6 EV has been checked. The car turns the
-        heater off by itself after about 10 minutes. Its state is reported
-        back in ``BasicVehicleStatus.steeringHeatLevel``.
+        Sends request type 8 with parameter 24 = 1 (on) or 0 (off), followed
+        by the end-of-parameters marker (255) like the other control
+        commands. The car turns the heater off by itself after about 10
+        minutes. Its state is reported back in
+        ``BasicVehicleStatus.steeringHeatLevel``.
         """
         rvc_params = [
             RvcParams(
                 RvcParamsId.HEATED_STEERING_WHEEL, b"\x01" if enable else b"\x00"
             ),
+            RvcParams(RvcParamsId.PARAMS_MAX, b"\x00\x00\x00\x00"),
         ]
         body = VehicleControlReq(
             rvc_req_type=RvcReqType.HEATED_STEERING_WHEEL,

tests/test_heated_seats.py

@@ -1,9 +1,9 @@
 """Per-seat heated seat control, front and rear (#34).
 
-Checks the request body against what the iSmart app sends (decrypted MG S6 EV
-traffic): request type 5, a single parameter for the chosen seat (17 front
-left, 18 front right, 25 rear left, 26 rear right) and no end-of-parameters
-marker. Rear seats are on/off only; the app sends 3 for "on".
+Checks the request body: request type 5, a single parameter for the chosen seat
+(17 front left, 18 front right, 25 rear left, 26 rear right), then the
+end-of-parameters marker (255). Rear seats are on/off only; the app sends 3 for
+"on".
 """
 
 from __future__ import annotations
@@ -58,7 +58,10 @@ async def test_one_seat_per_command(self) -> None:
                         (p.paramId, base64.b64decode(p.paramValue))
                         for p in body.rvcParams
                     ]
-                    assert params == [(param_id, bytes([level]))]
+                    assert params == [
+                        (param_id, bytes([level])),
+                        (255, b"\x00\x00\x00\x00"),
+                    ]
                     assert body.vin == sha256_hex_digest(VIN)
 
     async def test_rear_seat_on_is_the_apps_level(self) -> None:
@@ -67,7 +70,7 @@ async def test_rear_seat_on_is_the_apps_level(self) -> None:
             seat=HeatedSeat.REAR_LEFT, level=REAR_HEATED_SEAT_ON_LEVEL
         )
         params = [(p.paramId, base64.b64decode(p.paramValue)) for p in body.rvcParams]
-        assert params == [(25, b"\x03")]
+        assert params == [(25, b"\x03"), (255, b"\x00\x00\x00\x00")]
 
     async def test_out_of_range_levels_are_rejected(self) -> None:
         for level in (-1, 4):

tests/test_heated_steering_wheel.py

@@ -1,8 +1,7 @@
 """Heated steering wheel control (#33).
 
-Checks the request body against what the iSmart app sends (decrypted MG S6 EV
-traffic): request type 8, a single parameter 24 = 1 (on) or 0 (off), and no
-end-of-parameters marker.
+Checks the request body: request type 8, parameter 24 = 1 (on) or 0 (off),
+then the end-of-parameters marker (255).
 """
 
 from __future__ import annotations
@@ -39,11 +38,14 @@ async def test_on(self) -> None:
         assert body.rvcReqType == RvcReqType.HEATED_STEERING_WHEEL.value
         assert body.rvcReqType == "8"
         params = [(p.paramId, base64.b64decode(p.paramValue)) for p in body.rvcParams]
-        assert params == [(RvcParamsId.HEATED_STEERING_WHEEL.value, b"\x01")]
+        assert params == [
+            (RvcParamsId.HEATED_STEERING_WHEEL.value, b"\x01"),
+            (255, b"\x00\x00\x00\x00"),
+        ]
         assert params[0][0] == 24
         assert body.vin == sha256_hex_digest(VIN)
 
     async def test_off(self) -> None:
         body = await self._sent(enable=False)
         params = [(p.paramId, base64.b64decode(p.paramValue)) for p in body.rvcParams]
-        assert params == [(24, b"\x00")]
+        assert params == [(24, b"\x00"), (255, b"\x00\x00\x00\x00")]