diff --git a/backend/app/api/routes/printers.py b/backend/app/api/routes/printers.py
index 63e70d246..b64adccac 100644
--- a/backend/app/api/routes/printers.py
+++ b/backend/app/api/routes/printers.py
@@ -798,6 +798,8 @@ async def get_printer_status(
         big_fan1_speed=state.big_fan1_speed,
         big_fan2_speed=state.big_fan2_speed,
         heatbreak_fan_speed=state.heatbreak_fan_speed,
+        left_aux_fan_speed=state.left_aux_fan_speed,
+        exhaust_fan_present=state.exhaust_fan_present,
         firmware_version=state.firmware_version,
         developer_mode=state.developer_mode if state else None,
         ams_filament_backup=state.ams_filament_backup if state else None,
@@ -3193,16 +3195,22 @@ async def set_chamber_temperature(
 @router.post("/{printer_id}/fan-speed")
 async def set_fan_speed(
     printer_id: int,
-    fan: str = Query(..., description="Fan to control: part, aux, or chamber"),
+    fan: str = Query(..., description="Fan to control: part, aux, aux2 (left aux), or chamber"),
     speed: int = Query(..., ge=0, le=100, description="Fan speed percentage"),
     _=RequirePermissionIfAuthEnabled(Permission.PRINTERS_CONTROL),
     db: AsyncSession = Depends(get_db),
 ):
-    """Set a fan speed by percentage."""
-    fan_ids = {"part": 1, "aux": 2, "chamber": 3}
+    """Set a fan speed by percentage.
+
+    Fan index 10 ("aux2") is the optional left auxiliary part cooling fan on
+    P2S/X2D — driven with "M106 P10" exactly like Bambu's official machine
+    profile gcode does. It only exists when the accessory is installed; the
+    firmware silently ignores the command otherwise.
+    """
+    fan_ids = {"part": 1, "aux": 2, "chamber": 3, "aux2": 10}
     fan_id = fan_ids.get(fan)
     if fan_id is None:
-        raise HTTPException(400, "fan must be 'part', 'aux', or 'chamber'")
+        raise HTTPException(400, "fan must be 'part', 'aux', 'aux2', or 'chamber'")
 
     result = await db.execute(select(Printer).where(Printer.id == printer_id))
     printer = result.scalar_one_or_none()
@@ -3218,7 +3226,12 @@ async def set_fan_speed(
     if not success:
         raise HTTPException(500, "Failed to set fan speed")
 
-    fan_names = {"part": "Part cooling fan", "aux": "Auxiliary fan", "chamber": "Chamber fan"}
+    fan_names = {
+        "part": "Part cooling fan",
+        "aux": "Auxiliary fan",
+        "aux2": "Left auxiliary fan",
+        "chamber": "Chamber fan",
+    }
     return {"success": True, "message": f"{fan_names[fan]} set to {speed}%"}
 
 
diff --git a/backend/app/schemas/printer.py b/backend/app/schemas/printer.py
index e55486e62..ae9dad664 100644
--- a/backend/app/schemas/printer.py
+++ b/backend/app/schemas/printer.py
@@ -360,6 +360,11 @@ class PrinterStatus(BaseModel):
     big_fan1_speed: int | None = None  # Auxiliary fan
     big_fan2_speed: int | None = None  # Chamber/exhaust fan
     heatbreak_fan_speed: int | None = None  # Hotend heatbreak fan
+    # Left auxiliary part cooling fan (optional P2S/X2D accessory, airduct part id 10).
+    # None = not installed / not reported by this model.
+    left_aux_fan_speed: int | None = None
+    # Chamber exhaust fan present (P2S/X2D External Exhaust Fan kit; airduct part id 3).
+    exhaust_fan_present: bool = False
     # Firmware version (from info.module[name="ota"].sw_ver)
     firmware_version: str | None = None
     # Developer LAN mode: True = enabled, False = disabled (MQTT encryption), None = unknown
diff --git a/backend/app/services/bambu_mqtt.py b/backend/app/services/bambu_mqtt.py
index 6b9862a47..fa45be216 100644
--- a/backend/app/services/bambu_mqtt.py
+++ b/backend/app/services/bambu_mqtt.py
@@ -449,6 +449,14 @@ class PrinterState:
     big_fan1_speed: int | None = None  # Auxiliary fan
     big_fan2_speed: int | None = None  # Chamber/exhaust fan
     heatbreak_fan_speed: int | None = None  # Hotend heatbreak fan
+    # Left auxiliary part cooling fan (optional accessory on P2S/X2D). Reported ONLY
+    # via device.airduct.parts (decoded part id 10 = FAN_REMOTE_COOLING_1 in Bambu
+    # Studio's AIR_FUN enum) — the firmware does NOT mirror it into any flat
+    # big_fanX_speed field, which is why it was previously dropped. 0-100 percent.
+    left_aux_fan_speed: int | None = None
+    # Chamber exhaust fan (P2S/X2D External Exhaust Fan kit). Presence is derived
+    # from the airduct parts list containing decoded id 3; a base P2S omits it.
+    exhaust_fan_present: bool = False
     # Tray change history during current print: [(global_tray_id, layer_num), ...]
     # Used by usage tracker to split filament weight on mid-print tray switch
     tray_change_log: list = field(default_factory=list)
@@ -3215,6 +3223,45 @@ class BambuMQTTClient:
                             f"[{self.serial_number}] airduct_mode changed: {self.state.airduct_mode} -> {new_mode}"
                         )
                     self.state.airduct_mode = new_mode
+                # Parse individual airduct fan parts (new-protocol models: P2S/X2D/H2*).
+                # Raw part ids are bit-packed — decoded id = raw_id >> 4 (bits 4-11),
+                # mirroring Bambu Studio DevFan::ParseV3_0. Decoded ids follow the
+                # AIR_FUN enum: 1=part cooling, 2=right aux, 3=chamber/exhaust,
+                # 10=left aux (FAN_REMOTE_COOLING_1). The airduct `parts` list only
+                # contains the fans that physically exist, so it doubles as a
+                # presence signal for the two P2S/X2D add-on kits:
+                #   - id 10 (left auxiliary part cooling fan) — reported ONLY here,
+                #     never mirrored into a flat big_fanX_speed field.
+                #   - id 3 (chamber exhaust fan) — its speed is mirrored into
+                #     big_fan2_speed, but the part is only listed when the External
+                #     Exhaust Fan kit (get_version module "eef") is installed.
+                # `state` is already a 0-100 percentage.
+                parts = airduct_data.get("parts")
+                if isinstance(parts, list):
+                    left_aux_speed = None
+                    exhaust_present = False
+                    for part in parts:
+                        if not isinstance(part, dict):
+                            continue
+                        try:
+                            part_id = int(part["id"]) >> 4
+                            part_state = int(part["state"])
+                        except (KeyError, ValueError, TypeError):
+                            continue
+                        if part_id == 10:
+                            left_aux_speed = max(0, min(100, part_state))
+                        elif part_id == 3:
+                            exhaust_present = True
+                    if left_aux_speed != self.state.left_aux_fan_speed:
+                        logger.debug(
+                            f"[{self.serial_number}] left_aux_fan_speed changed: "
+                            f"{self.state.left_aux_fan_speed} -> {left_aux_speed}"
+                        )
+                    # A full parts list without id 10 means the left aux fan is not
+                    # installed — report None so the UI can hide the widget.
+                    self.state.left_aux_fan_speed = left_aux_speed
+                    # id 3 present == chamber exhaust fan installed (base P2S omits it).
+                    self.state.exhaust_fan_present = exhaust_present
                 # Parse chamber temp - may be encoded as (target*65536+current) when > 500
                 # Check if we recently set the target locally (within 5 seconds)
                 local_set_time = self.state.temperatures.get("_chamber_target_set_time", 0)
@@ -5463,13 +5510,16 @@ class BambuMQTTClient:
         """Set fan speed.
 
         Args:
-            fan: Fan index (1=part cooling, 2=auxiliary, 3=chamber)
+            fan: Fan index (1=part cooling, 2=auxiliary, 3=chamber, 10=left auxiliary).
+                Index 10 is the optional left auxiliary part cooling fan on P2S/X2D
+                (airduct part id 10); Bambu's official machine profiles drive it with
+                "M106 P10" in start/layer-change gcode.
             speed: Speed 0-255 (0=off, 255=full)
 
         Returns:
             True if command was sent, False otherwise
         """
-        if fan not in (1, 2, 3):
+        if fan not in (1, 2, 3, 10):
             logger.warning("[%s] Invalid fan index: %s", self.serial_number, fan)
             return False
 
@@ -5488,6 +5538,10 @@ class BambuMQTTClient:
         """Set chamber fan speed (0-255)."""
         return self.set_fan_speed(3, speed)
 
+    def set_left_aux_fan(self, speed: int) -> bool:
+        """Set left auxiliary part cooling fan speed (0-255). P2S/X2D accessory."""
+        return self.set_fan_speed(10, speed)
+
     def set_airduct_mode(self, mode: str) -> bool:
         """Set air conditioning mode (cooling or heating).
 
diff --git a/backend/app/services/mqtt_relay.py b/backend/app/services/mqtt_relay.py
index 0150dc652..8f04d48cb 100644
--- a/backend/app/services/mqtt_relay.py
+++ b/backend/app/services/mqtt_relay.py
@@ -282,6 +282,8 @@ class MQTTRelayService:
             "big_fan1_speed": state.big_fan1_speed,
             "big_fan2_speed": state.big_fan2_speed,
             "heatbreak_fan_speed": state.heatbreak_fan_speed,
+            "left_aux_fan_speed": state.left_aux_fan_speed,
+            "exhaust_fan_present": state.exhaust_fan_present,
             # Bambuddy-side gate, not printer telemetry (#2525). Mirrors what the
             # Web UI already receives via printer_state_to_dict, so an external
             # automation can tell "finished" from "finished and still waiting for
diff --git a/backend/app/services/printer_manager.py b/backend/app/services/printer_manager.py
index 9729569ce..903d26984 100644
--- a/backend/app/services/printer_manager.py
+++ b/backend/app/services/printer_manager.py
@@ -1413,6 +1413,8 @@ def printer_state_to_dict(
         "big_fan1_speed": state.big_fan1_speed,
         "big_fan2_speed": state.big_fan2_speed,
         "heatbreak_fan_speed": state.heatbreak_fan_speed,
+        "left_aux_fan_speed": state.left_aux_fan_speed,
+        "exhaust_fan_present": state.exhaust_fan_present,
         # Chamber light state
         "chamber_light": state.chamber_light,
         # Active extruder for dual-nozzle printers (0=right, 1=left)
diff --git a/backend/tests/integration/test_printers_api.py b/backend/tests/integration/test_printers_api.py
index 6cd4abef8..e75cc2e9d 100644
--- a/backend/tests/integration/test_printers_api.py
+++ b/backend/tests/integration/test_printers_api.py
@@ -3855,8 +3855,10 @@ class TestSetChamberTemperatureAPI:
 class TestSetFanSpeedAPI:
     """Integration tests for POST /printers/{id}/fan-speed (#1661).
 
-    The fan-id mapping (part->1, aux->2, chamber->3) is the critical
-    correctness gate — wrong mapping would target the wrong physical fan.
+    The fan-id mapping (part->1, aux->2, chamber->3, aux2->10) is the
+    critical correctness gate — wrong mapping would target the wrong
+    physical fan. "aux2" (M106 P10) is the optional left auxiliary part
+    cooling fan on P2S/X2D.
     """
 
     @pytest.mark.asyncio
@@ -3879,7 +3881,7 @@ class TestSetFanSpeedAPI:
     @pytest.mark.integration
     @pytest.mark.parametrize(
         "fan_name,expected_fan_id",
-        [("part", 1), ("aux", 2), ("chamber", 3)],
+        [("part", 1), ("aux", 2), ("chamber", 3), ("aux2", 10)],
     )
     async def test_fan_id_mapping(self, async_client: AsyncClient, printer_factory, fan_name, expected_fan_id):
         """Verify each fan name maps to the correct hardware fan-id."""
diff --git a/backend/tests/unit/services/test_p2s_accessory_fans.py b/backend/tests/unit/services/test_p2s_accessory_fans.py
new file mode 100644
index 000000000..1ff40d23d
--- /dev/null
+++ b/backend/tests/unit/services/test_p2s_accessory_fans.py
@@ -0,0 +1,207 @@
+"""Tests for the P2S/X2D left auxiliary part cooling fan (#2576).
+
+The "Auxiliary Part Cooling Fan - Left" (also fits X2D) is reported ONLY as
+device.airduct part with raw id 160 (decoded id = 160 >> 4 = 10,
+AIR_FUN.FAN_REMOTE_COOLING_1 in Bambu Studio) — the firmware does NOT mirror
+it into any flat big_fanX_speed field, which is why it was previously dropped.
+It is controlled with "M106 P10", exactly like Bambu's official P2S machine-
+profile gcode does.
+
+The airduct payloads below are verbatim captures from a live P2S
+(fw 01.02.00.00) with the accessory installed.
+"""
+
+import pytest
+
+
+@pytest.fixture
+def mqtt_client():
+    from backend.app.services.bambu_mqtt import BambuMQTTClient
+
+    return BambuMQTTClient(
+        ip_address="192.168.1.100",
+        serial_number="TESTP2S",
+        access_code="12345678",
+    )
+
+
+def _airduct_device(parts):
+    """Wrap airduct parts in the device envelope as pushed by a P2S."""
+    return {
+        "device": {
+            "airduct": {
+                "modeCur": 0,
+                "modeFunc": 0,
+                "modeList": [
+                    {"ctrl": [16, 32, 160, 48], "modeId": 0, "off": []},
+                    {"ctrl": [16, 32, 48], "modeId": 1, "off": [160]},
+                ],
+                "modeVisable": 7,
+                "parts": parts,
+                "subFunc": 0,
+                "subMode": 0,
+                "subVisable": 7,
+                "version": 1,
+            },
+            "type": 1,
+        }
+    }
+
+
+# Verbatim parts list from a live P2S: part cooling ramping (state 30,
+# target 90), right aux at 40%, left aux OFF, chamber at 70%.
+P2S_PARTS_LEFT_AUX_OFF = [
+    {"func": 0, "id": 16, "range": 6553600, "state": 30, "tar_state": 90},
+    {"func": 6, "id": 32, "range": 6553600, "state": 40, "tar_state": 40},
+    {"func": 5, "id": 160, "range": 6553600, "state": 0, "tar_state": 0},
+    {"func": 2, "id": 48, "range": 6553600, "state": 70, "tar_state": 70},
+]
+
+# Same printer later in the print: left aux running at 80%.
+P2S_PARTS_LEFT_AUX_80 = [
+    {"func": 0, "id": 16, "range": 6553600, "state": 60, "tar_state": 60},
+    {"func": 6, "id": 32, "range": 6553600, "state": 100, "tar_state": 100},
+    {"func": 5, "id": 160, "range": 6553600, "state": 80, "tar_state": 80},
+    {"func": 2, "id": 48, "range": 6553600, "state": 80, "tar_state": 80},
+]
+
+
+class TestLeftAuxFanParsing:
+    """device.airduct part id 10 (raw 160) -> state.left_aux_fan_speed."""
+
+    def test_defaults_to_none(self, mqtt_client):
+        assert mqtt_client.state.left_aux_fan_speed is None
+
+    def test_parses_left_aux_running(self, mqtt_client):
+        mqtt_client._update_state(_airduct_device(P2S_PARTS_LEFT_AUX_80))
+        assert mqtt_client.state.left_aux_fan_speed == 80
+
+    def test_parses_left_aux_off(self, mqtt_client):
+        mqtt_client._update_state(_airduct_device(P2S_PARTS_LEFT_AUX_OFF))
+        assert mqtt_client.state.left_aux_fan_speed == 0
+
+    def test_raw_id_is_bit_unpacked(self, mqtt_client):
+        """Raw id 160 must decode to part id 10 (id >> 4), NOT match on 160."""
+        # A hypothetical raw id of 10 would decode to part id 0 — must not match.
+        parts = [{"func": 5, "id": 10, "range": 6553600, "state": 50, "tar_state": 50}]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.left_aux_fan_speed is None
+
+    def test_parts_without_left_aux_reports_none(self, mqtt_client):
+        """A full parts list without id 10 means the fan is not installed."""
+        mqtt_client.state.left_aux_fan_speed = 80  # previously seen
+        parts = [p for p in P2S_PARTS_LEFT_AUX_80 if p["id"] != 160]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.left_aux_fan_speed is None
+
+    def test_diff_push_without_device_preserves_value(self, mqtt_client):
+        """P-series diff pushes omit device.airduct — value must survive."""
+        mqtt_client._update_state(_airduct_device(P2S_PARTS_LEFT_AUX_80))
+        mqtt_client._update_state({"nozzle_temper": 250.0})
+        assert mqtt_client.state.left_aux_fan_speed == 80
+
+    def test_state_clamped_to_0_100(self, mqtt_client):
+        parts = [{"func": 5, "id": 160, "range": 6553600, "state": 250, "tar_state": 0}]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.left_aux_fan_speed == 100
+
+    def test_malformed_part_entries_ignored(self, mqtt_client):
+        parts = [
+            "not-a-dict",
+            {"func": 5},  # no id/state
+            {"id": "garbage", "state": 10},
+            {"func": 5, "id": 160, "range": 6553600, "state": 30, "tar_state": 30},
+        ]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.left_aux_fan_speed == 30
+
+    def test_flat_fan_fields_unaffected(self, mqtt_client):
+        """Regression: flat fields keep coming from the flat MQTT keys."""
+        payload = {
+            "cooling_fan_speed": "4",
+            "big_fan1_speed": "6",
+            "big_fan2_speed": "10",
+            "heatbreak_fan_speed": "14",
+            **_airduct_device(P2S_PARTS_LEFT_AUX_OFF),
+        }
+        mqtt_client._update_state(payload)
+        assert mqtt_client.state.cooling_fan_speed == 27  # 4/15
+        assert mqtt_client.state.big_fan1_speed == 40  # 6/15
+        assert mqtt_client.state.big_fan2_speed == 67  # 10/15
+        assert mqtt_client.state.heatbreak_fan_speed == 93  # 14/15
+        assert mqtt_client.state.left_aux_fan_speed == 0
+
+
+class TestExhaustFanPresence:
+    """device.airduct part id 3 (raw 48) presence -> state.exhaust_fan_present.
+
+    The chamber exhaust fan is a P2S/X2D add-on kit (get_version module "eef").
+    Its speed rides on the flat big_fan2_speed field, but the airduct only lists
+    part id 3 when the kit is physically installed — so part-3 presence is the
+    signal the UI uses to show/hide the Exhaust tile.
+    """
+
+    def test_defaults_to_false(self, mqtt_client):
+        assert mqtt_client.state.exhaust_fan_present is False
+
+    def test_present_when_part_3_reported(self, mqtt_client):
+        # Full P2S parts list includes id 48 (>>4 = 3).
+        mqtt_client._update_state(_airduct_device(P2S_PARTS_LEFT_AUX_80))
+        assert mqtt_client.state.exhaust_fan_present is True
+
+    def test_absent_when_part_3_missing(self, mqtt_client):
+        mqtt_client.state.exhaust_fan_present = True  # previously seen
+        parts = [p for p in P2S_PARTS_LEFT_AUX_80 if p["id"] != 48]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.exhaust_fan_present is False
+
+    def test_base_p2s_only_part_cooling_and_aux(self, mqtt_client):
+        # A base P2S (no exhaust kit, no left aux kit) lists only ids 1 and 2.
+        parts = [
+            {"func": 0, "id": 16, "range": 6553600, "state": 0, "tar_state": 0},
+            {"func": 6, "id": 32, "range": 6553600, "state": 0, "tar_state": 0},
+        ]
+        mqtt_client._update_state(_airduct_device(parts))
+        assert mqtt_client.state.exhaust_fan_present is False
+        assert mqtt_client.state.left_aux_fan_speed is None
+
+    def test_diff_push_without_device_preserves_value(self, mqtt_client):
+        mqtt_client._update_state(_airduct_device(P2S_PARTS_LEFT_AUX_80))
+        mqtt_client._update_state({"nozzle_temper": 250.0})
+        assert mqtt_client.state.exhaust_fan_present is True
+
+
+class TestLeftAuxFanCommand:
+    """set_fan_speed must accept index 10 and emit M106 P10."""
+
+    def test_set_fan_speed_10_sends_m106_p10(self, mqtt_client, monkeypatch):
+        sent = []
+        monkeypatch.setattr(mqtt_client, "send_gcode", lambda g: sent.append(g) or True)
+        assert mqtt_client.set_fan_speed(10, 204) is True
+        assert sent == ["M106 P10 S204"]
+
+    def test_set_left_aux_fan_helper(self, mqtt_client, monkeypatch):
+        sent = []
+        monkeypatch.setattr(mqtt_client, "send_gcode", lambda g: sent.append(g) or True)
+        assert mqtt_client.set_left_aux_fan(255) is True
+        assert sent == ["M106 P10 S255"]
+
+    def test_speed_clamped_to_255(self, mqtt_client, monkeypatch):
+        sent = []
+        monkeypatch.setattr(mqtt_client, "send_gcode", lambda g: sent.append(g) or True)
+        mqtt_client.set_left_aux_fan(999)
+        assert sent == ["M106 P10 S255"]
+
+    def test_invalid_fan_index_rejected(self, mqtt_client, monkeypatch):
+        sent = []
+        monkeypatch.setattr(mqtt_client, "send_gcode", lambda g: sent.append(g) or True)
+        assert mqtt_client.set_fan_speed(4, 100) is False
+        assert mqtt_client.set_fan_speed(11, 100) is False
+        assert sent == []
+
+    def test_existing_fan_indexes_still_accepted(self, mqtt_client, monkeypatch):
+        sent = []
+        monkeypatch.setattr(mqtt_client, "send_gcode", lambda g: sent.append(g) or True)
+        for idx in (1, 2, 3):
+            assert mqtt_client.set_fan_speed(idx, 128) is True
+        assert sent == ["M106 P1 S128", "M106 P2 S128", "M106 P3 S128"]
diff --git a/backend/tests/unit/test_printer_manager_status_broadcast.py b/backend/tests/unit/test_printer_manager_status_broadcast.py
index 229328c21..3ddc2dcda 100644
--- a/backend/tests/unit/test_printer_manager_status_broadcast.py
+++ b/backend/tests/unit/test_printer_manager_status_broadcast.py
@@ -90,6 +90,8 @@ def _fake_state(**overrides):
         "firmware_version": None,
         "gcode_file": None,
         "heatbreak_fan_speed": None,
+        "left_aux_fan_speed": None,
+        "exhaust_fan_present": False,
         "layer_num": None,
         "remaining_time": None,
         "speed_level": None,
diff --git a/frontend/src/__tests__/pages/PrintersPage.test.tsx b/frontend/src/__tests__/pages/PrintersPage.test.tsx
index c8b0f8cb1..216de553e 100644
--- a/frontend/src/__tests__/pages/PrintersPage.test.tsx
+++ b/frontend/src/__tests__/pages/PrintersPage.test.tsx
@@ -310,6 +310,91 @@ describe('PrintersPage', () => {
         expect(screen.getByTitle('Chamber Fan')).toBeInTheDocument();
       });
     });
+
+    // P2S/X2D left auxiliary part cooling fan (airduct part id 10) — optional
+    // hardware, so the badge must only appear when the firmware reports it.
+    const renderWithStatus = (
+      printer: typeof mockPrinters[number],
+      status: Record<string, unknown>,
+    ) => {
+      server.use(
+        http.get('/api/v1/printers/', () => HttpResponse.json([printer])),
+        http.get('/api/v1/printers/:id/status', () => HttpResponse.json(status)),
+      );
+      render(<PrintersPage />);
+    };
+
+    it('shows the exhaust tile labeled "Exhaust" on P2S when the kit is present', async () => {
+      // Exhaust fan is an add-on kit; the tile appears only when the printer
+      // reports it (airduct part id 3 -> exhaust_fan_present).
+      renderWithStatus(
+        { ...mockPrinters[0], model: 'P2S' },
+        { ...statusWithFans, exhaust_fan_present: true },
+      );
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Part Cooling Fan')).toBeInTheDocument();
+      });
+      expect(screen.getByTitle('Exhaust')).toBeInTheDocument();
+      expect(screen.queryByTitle('Chamber Fan')).not.toBeInTheDocument();
+    });
+
+    it('hides the exhaust tile on a base P2S without the kit', async () => {
+      renderWithStatus(
+        { ...mockPrinters[0], model: 'P2S' },
+        { ...statusWithFans, exhaust_fan_present: false },
+      );
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Part Cooling Fan')).toBeInTheDocument();
+      });
+      expect(screen.queryByTitle('Exhaust')).not.toBeInTheDocument();
+      expect(screen.queryByTitle('Chamber Fan')).not.toBeInTheDocument();
+    });
+
+    it('keeps the always-on "Chamber Fan" tile on X1C regardless of exhaust_fan_present', async () => {
+      renderWithStatus(
+        { ...mockPrinters[0], model: 'X1C' },
+        { ...statusWithFans, exhaust_fan_present: false },
+      );
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Chamber Fan')).toBeInTheDocument();
+      });
+      expect(screen.queryByTitle('Exhaust')).not.toBeInTheDocument();
+    });
+
+    it('hides the left aux badge when the accessory is not reported', async () => {
+      renderWithStatus({ ...mockPrinters[0], model: 'P2S' }, statusWithFans);
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Part Cooling Fan')).toBeInTheDocument();
+      });
+      expect(screen.queryByTitle('Left Auxiliary Fan')).not.toBeInTheDocument();
+    });
+
+    it('shows left aux fan badge when the accessory is installed (P2S)', async () => {
+      renderWithStatus(
+        { ...mockPrinters[0], model: 'P2S' },
+        { ...statusWithFans, left_aux_fan_speed: 80 },
+      );
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Left Auxiliary Fan')).toBeInTheDocument();
+      });
+    });
+
+    it('shows left aux fan badge even at 0% while installed', async () => {
+      renderWithStatus(
+        { ...mockPrinters[0], model: 'P2S' },
+        { ...statusWithFans, left_aux_fan_speed: 0 },
+      );
+
+      await waitFor(() => {
+        expect(screen.getByTitle('Left Auxiliary Fan')).toBeInTheDocument();
+      });
+    });
+
   });
 
   describe('empty state', () => {
diff --git a/frontend/src/api/client.ts b/frontend/src/api/client.ts
index f9cbbb212..f08d987d9 100644
--- a/frontend/src/api/client.ts
+++ b/frontend/src/api/client.ts
@@ -565,6 +565,11 @@ export interface PrinterStatus {
   big_fan1_speed: number | null;     // Auxiliary fan
   big_fan2_speed: number | null;     // Chamber/exhaust fan
   heatbreak_fan_speed: number | null; // Hotend heatbreak fan
+  // Left auxiliary part cooling fan (optional P2S/X2D accessory, M106 P10).
+  // null = not installed / not reported by this model.
+  left_aux_fan_speed: number | null;
+  // Chamber exhaust fan present (P2S/X2D External Exhaust Fan kit, airduct part 3).
+  exhaust_fan_present: boolean;
   firmware_version: string | null;   // Firmware version from MQTT
   // Developer LAN mode: true = enabled, false = disabled, null = unknown
   developer_mode: boolean | null;
@@ -3934,7 +3939,7 @@ export const api = {
       method: 'POST',
     }),
 
-  setFanSpeed: (printerId: number, fan: 'part' | 'aux' | 'chamber', speed: number) =>
+  setFanSpeed: (printerId: number, fan: 'part' | 'aux' | 'aux2' | 'chamber', speed: number) =>
     request<{ success: boolean; message: string }>(`/printers/${printerId}/fan-speed?fan=${fan}&speed=${speed}`, {
       method: 'POST',
     }),
diff --git a/frontend/src/i18n/locales/de.ts b/frontend/src/i18n/locales/de.ts
index 753047ab8..76b98d260 100644
--- a/frontend/src/i18n/locales/de.ts
+++ b/frontend/src/i18n/locales/de.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Bauteilkühlung',
       auxiliary: 'Hilfsventilator',
+      leftAuxiliary: 'Linker Hilfsventilator',
+      exhaust: 'Abluft',
       chamber: 'Kammerventilator',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
index 701c02806..165f31bb3 100644
--- a/frontend/src/i18n/locales/en.ts
+++ b/frontend/src/i18n/locales/en.ts
@@ -672,6 +672,8 @@ export default {
     fans: {
       partCooling: 'Part Cooling Fan',
       auxiliary: 'Auxiliary Fan',
+      leftAuxiliary: 'Left Auxiliary Fan',
+      exhaust: 'Exhaust',
       chamber: 'Chamber Fan',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/es.ts b/frontend/src/i18n/locales/es.ts
index a9b9de4c6..10676cbda 100644
--- a/frontend/src/i18n/locales/es.ts
+++ b/frontend/src/i18n/locales/es.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Ventilador de refrigeración de piezas',
       auxiliary: 'Ventilador auxiliar',
+      leftAuxiliary: 'Ventilador auxiliar izquierdo',
+      exhaust: 'Extracción',
       chamber: 'Ventilador de la cámara',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/fr.ts b/frontend/src/i18n/locales/fr.ts
index 6b1d4c9f4..18277b8e5 100644
--- a/frontend/src/i18n/locales/fr.ts
+++ b/frontend/src/i18n/locales/fr.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Ventilateur pièce',
       auxiliary: 'Ventilateur auxiliaire',
+      leftAuxiliary: 'Ventilateur auxiliaire gauche',
+      exhaust: 'Extraction',
       chamber: 'Ventilateur chambre',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/it.ts b/frontend/src/i18n/locales/it.ts
index 92fb9a9ab..7449d91fd 100644
--- a/frontend/src/i18n/locales/it.ts
+++ b/frontend/src/i18n/locales/it.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Ventola raffreddamento parte',
       auxiliary: 'Ventola ausiliaria',
+      leftAuxiliary: 'Ventola ausiliaria sinistra',
+      exhaust: 'Estrazione',
       chamber: 'Ventola camera',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/ja.ts b/frontend/src/i18n/locales/ja.ts
index 9c47c08c6..74e49567f 100644
--- a/frontend/src/i18n/locales/ja.ts
+++ b/frontend/src/i18n/locales/ja.ts
@@ -667,6 +667,8 @@ export default {
     fans: {
       partCooling: 'パーツ冷却ファン',
       auxiliary: '補助ファン',
+      leftAuxiliary: '左補助ファン',
+      exhaust: '排気',
       chamber: 'チャンバーファン',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/ko.ts b/frontend/src/i18n/locales/ko.ts
index 29d728726..154e7839a 100644
--- a/frontend/src/i18n/locales/ko.ts
+++ b/frontend/src/i18n/locales/ko.ts
@@ -625,6 +625,8 @@ export default {
     fans: {
       partCooling: '파트 냉각 팬',
       auxiliary: '보조 팬',
+      leftAuxiliary: '왼쪽 보조 팬',
+      exhaust: '배기',
       chamber: '챔버 팬'
     },
     clickToViewHmsErrors: 'HMS 오류 보기 클릭',
diff --git a/frontend/src/i18n/locales/pt-BR.ts b/frontend/src/i18n/locales/pt-BR.ts
index 81f62a625..a91466923 100644
--- a/frontend/src/i18n/locales/pt-BR.ts
+++ b/frontend/src/i18n/locales/pt-BR.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Ventilador de resfriamento da peça',
       auxiliary: 'Ventilador auxiliar',
+      leftAuxiliary: 'Ventilador auxiliar esquerdo',
+      exhaust: 'Exaustão',
       chamber: 'Ventilador da câmara',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/ru.ts b/frontend/src/i18n/locales/ru.ts
index 149df02e4..88b771d3a 100644
--- a/frontend/src/i18n/locales/ru.ts
+++ b/frontend/src/i18n/locales/ru.ts
@@ -630,6 +630,8 @@ export default {
     fans: {
       partCooling: "Вентилятор обдува модели",
       auxiliary: "Дополнительный вентилятор",
+      leftAuxiliary: "Левый дополнительный вентилятор",
+      exhaust: "Вытяжка",
       chamber: "Вентилятор камеры",
     },
     clickToViewHmsErrors: "Нажмите, чтобы посмотреть ошибки HMS",
diff --git a/frontend/src/i18n/locales/tr.ts b/frontend/src/i18n/locales/tr.ts
index f264a339c..333c50768 100644
--- a/frontend/src/i18n/locales/tr.ts
+++ b/frontend/src/i18n/locales/tr.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: 'Parça Soğutma Fanı',
       auxiliary: 'Yardımcı Fan',
+      leftAuxiliary: 'Sol Yardımcı Fan',
+      exhaust: 'Egzoz',
       chamber: 'Hazne Fanı',
     },
     // HMS hataları
diff --git a/frontend/src/i18n/locales/zh-CN.ts b/frontend/src/i18n/locales/zh-CN.ts
index 6a3e21e53..b35851780 100644
--- a/frontend/src/i18n/locales/zh-CN.ts
+++ b/frontend/src/i18n/locales/zh-CN.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: '零件冷却风扇',
       auxiliary: '辅助风扇',
+      leftAuxiliary: '左辅助风扇',
+      exhaust: '排气',
       chamber: '腔室风扇',
     },
     // HMS errors
diff --git a/frontend/src/i18n/locales/zh-TW.ts b/frontend/src/i18n/locales/zh-TW.ts
index 219c4e3f4..5d911f00a 100644
--- a/frontend/src/i18n/locales/zh-TW.ts
+++ b/frontend/src/i18n/locales/zh-TW.ts
@@ -668,6 +668,8 @@ export default {
     fans: {
       partCooling: '零件冷卻風扇',
       auxiliary: '輔助風扇',
+      leftAuxiliary: '左輔助風扇',
+      exhaust: '排氣',
       chamber: '腔室風扇',
     },
     // HMS errors
diff --git a/frontend/src/pages/PrintersPage.tsx b/frontend/src/pages/PrintersPage.tsx
index 193af952f..229e52b06 100644
--- a/frontend/src/pages/PrintersPage.tsx
+++ b/frontend/src/pages/PrintersPage.tsx
@@ -1490,6 +1490,17 @@ const MODELS_WITH_CHAMBER_FAN: ReadonlySet<string> = new Set([
   'H2S',
 ]);
 
+// On the P2S/X2D, the enclosure fan (big_fan2 / airduct part id 3) is a
+// dedicated chamber EXHAUST fan: it's its own control and stays the same
+// regardless of cooling/heating mode (unlike the aux fan, id 2, which a flap
+// re-tasks between part-cooling and chamber-filter recirculation). Bambu's own
+// firmware/UI and Bambu Studio (FAN_CHAMBER_0_IDX -> "Exhaust") label it
+// "Exhaust" on these models. Other enclosed models (X1/P1S/H2*) keep "Chamber".
+const MODELS_WITH_EXHAUST_LABEL: ReadonlySet<string> = new Set([
+  'P2S',
+  'X2D',
+]);
+
 // Map SSDP model codes to display names
 function mapModelCode(ssdpModel: string | null): string {
   if (!ssdpModel) return '';
@@ -2449,7 +2460,7 @@ function PrinterCard({
   });
 
   const fanSpeedMutation = useMutation({
-    mutationFn: ({ fan, speed }: { fan: 'part' | 'aux' | 'chamber'; speed: number }) =>
+    mutationFn: ({ fan, speed }: { fan: 'part' | 'aux' | 'aux2' | 'chamber'; speed: number }) =>
       api.setFanSpeed(printer.id, fan, speed),
     onMutate: async ({ fan, speed }) => {
       await queryClient.cancelQueries({ queryKey: ['printerStatus', printer.id] });
@@ -2457,6 +2468,7 @@ function PrinterCard({
       const fanField = {
         part: 'cooling_fan_speed',
         aux: 'big_fan1_speed',
+        aux2: 'left_aux_fan_speed',
         chamber: 'big_fan2_speed',
       }[fan];
       queryClient.setQueryData(['printerStatus', printer.id], (old: PrinterStatus | undefined) =>
@@ -3886,7 +3898,24 @@ function PrinterCard({
               // control that does nothing. Mirrors the enclosure-door badge
               // gate above.
               const hasChamberFan = MODELS_WITH_CHAMBER_FAN.has(printer.model ?? '');
-              const fanItems = [
+              // On P2S/X2D the big_fan2 fan is the dedicated chamber EXHAUST fan
+              // ("Exhaust" in Bambu's naming) and is an add-on kit, not preinstalled:
+              // show it only when the printer actually reports it (airduct part id 3,
+              // surfaced as exhaust_fan_present). Other enclosed models (X1/P1S/H2*)
+              // have a built-in chamber fan that's always present, so they keep the
+              // existing model-list gate and the "Chamber Fan" label.
+              const isExhaustModel = MODELS_WITH_EXHAUST_LABEL.has(printer.model ?? '');
+              const chamberFanLabel = isExhaustModel
+                ? t('printers.fans.exhaust')
+                : t('printers.fans.chamber');
+              const showChamberFan = isExhaustModel ? status.exhaust_fan_present : hasChamberFan;
+              const fanItems: {
+                key: string;
+                label: string;
+                value: number;
+                Icon: typeof Fan;
+                activeClass: string;
+              }[] = [
                 {
                   key: 'part',
                   label: t('printers.fans.partCooling'),
@@ -3901,11 +3930,25 @@ function PrinterCard({
                   Icon: Wind,
                   activeClass: 'text-blue-600 dark:text-blue-400',
                 },
-                ...(hasChamberFan
+                // Left auxiliary part cooling fan (optional P2S/X2D accessory).
+                // Only reported (non-null) when the firmware lists airduct part
+                // id 10, i.e. when the fan is physically installed.
+                ...(status.left_aux_fan_speed != null
+                  ? [
+                      {
+                        key: 'aux2',
+                        label: t('printers.fans.leftAuxiliary'),
+                        value: status.left_aux_fan_speed,
+                        Icon: Wind,
+                        activeClass: 'text-indigo-600 dark:text-indigo-400',
+                      },
+                    ]
+                  : []),
+                ...(showChamberFan
                   ? [
                       {
                         key: 'chamber',
-                        label: t('printers.fans.chamber'),
+                        label: chamberFanLabel,
                         value: status.big_fan2_speed ?? 0,
                         Icon: AirVent,
                         activeClass: 'text-green-600 dark:text-green-400',
@@ -4157,7 +4200,7 @@ function PrinterCard({
                               isPending={fanSpeedMutation.isPending}
                               options={buildPresetOptions(fanSpeedPresets, '%')}
                               onClose={() => setStatusControlMenu(null)}
-                              onSubmit={(speed) => fanSpeedMutation.mutate({ fan: key as 'part' | 'aux' | 'chamber', speed })}
+                              onSubmit={(speed) => fanSpeedMutation.mutate({ fan: key as 'part' | 'aux' | 'aux2' | 'chamber', speed })}
                             />
                           )}
                         </div>