diff --git a/homeassistant/components/modbus/__init__.py b/homeassistant/components/modbus/__init__.py
index 0108c37a10b..920188603fc 100644
--- a/homeassistant/components/modbus/__init__.py
+++ b/homeassistant/components/modbus/__init__.py
@@ -55,7 +55,6 @@ from .const import (  # noqa: F401
     CALL_TYPE_DISCRETE,
     CALL_TYPE_REGISTER_HOLDING,
     CALL_TYPE_REGISTER_INPUT,
-    CALL_TYPE_WRITE_REGISTER,
     CALL_TYPE_X_COILS,
     CALL_TYPE_X_REGISTER_HOLDINGS,
     CONF_BAUDRATE,
@@ -64,7 +63,6 @@ from .const import (  # noqa: F401
     CONF_CLOSE_COMM_ON_ERROR,
     CONF_DATA_TYPE,
     CONF_FANS,
-    CONF_HUB,
     CONF_HVAC_MODE_AUTO,
     CONF_HVAC_MODE_COOL,
     CONF_HVAC_MODE_DRY,
diff --git a/homeassistant/components/modbus/const.py b/homeassistant/components/modbus/const.py
index 3b565e91f92..e509577267c 100644
--- a/homeassistant/components/modbus/const.py
+++ b/homeassistant/components/modbus/const.py
@@ -16,13 +16,8 @@ CONF_BAUDRATE = "baudrate"
 CONF_BYTESIZE = "bytesize"
 CONF_CLIMATES = "climates"
 CONF_CLOSE_COMM_ON_ERROR = "close_comm_on_error"
-CONF_COILS = "coils"
-CONF_CURRENT_TEMP = "current_temp_register"
-CONF_CURRENT_TEMP_REGISTER_TYPE = "current_temp_register_type"
 CONF_DATA_TYPE = "data_type"
 CONF_FANS = "fans"
-CONF_HUB = "hub"
-CONF_INPUTS = "inputs"
 CONF_INPUT_TYPE = "input_type"
 CONF_LAZY_ERROR = "lazy_error_count"
 CONF_MAX_TEMP = "max_temp"
@@ -32,9 +27,6 @@ CONF_MIN_VALUE = "min_value"
 CONF_MSG_WAIT = "message_wait_milliseconds"
 CONF_NAN_VALUE = "nan_value"
 CONF_PARITY = "parity"
-CONF_REGISTER = "register"
-CONF_REGISTER_TYPE = "register_type"
-CONF_REGISTERS = "registers"
 CONF_RETRIES = "retries"
 CONF_RETRY_ON_EMPTY = "retry_on_empty"
 CONF_PRECISION = "precision"
@@ -69,8 +61,6 @@ CONF_HVAC_MODE_DRY = "state_dry"
 CONF_HVAC_MODE_FAN_ONLY = "state_fan_only"
 CONF_WRITE_REGISTERS = "write_registers"
 CONF_VERIFY = "verify"
-CONF_VERIFY_REGISTER = "verify_register"
-CONF_VERIFY_STATE = "verify_state"
 CONF_WRITE_TYPE = "write_type"
 CONF_ZERO_SUPPRESS = "zero_suppress"
 
@@ -82,7 +72,7 @@ UDP = "udp"
 
 # service call attributes
 ATTR_ADDRESS = CONF_ADDRESS
-ATTR_HUB = CONF_HUB
+ATTR_HUB = "hub"
 ATTR_UNIT = "unit"
 ATTR_SLAVE = "slave"
 ATTR_VALUE = "value"
diff --git a/tests/components/modbus/test_init.py b/tests/components/modbus/test_init.py
index d9d3b035c94..35c01ec478b 100644
--- a/tests/components/modbus/test_init.py
+++ b/tests/components/modbus/test_init.py
@@ -929,3 +929,20 @@ async def test_integration_reload_failed(
 
     assert "Modbus reloading" in caplog.text
     assert "connect failed, retry in pymodbus" in caplog.text
+
+
+@pytest.mark.parametrize("do_config", [{}])
+async def test_integration_setup_failed(
+    hass: HomeAssistant, caplog: pytest.LogCaptureFixture, mock_modbus
+) -> None:
+    """Run test for integration setup on reload."""
+    with mock.patch.object(
+        hass_config,
+        "YAML_CONFIG_FILE",
+        get_fixture_path("configuration.yaml", "modbus"),
+    ):
+        hass.data[DOMAIN][TEST_MODBUS_NAME].async_setup = mock.AsyncMock(
+            return_value=False
+        )
+        await hass.services.async_call(DOMAIN, SERVICE_RELOAD, blocking=True)
+        await hass.async_block_till_done()
diff --git a/tests/components/modbus/test_sensor.py b/tests/components/modbus/test_sensor.py
index 48a081ef637..06b0b68a746 100644
--- a/tests/components/modbus/test_sensor.py
+++ b/tests/components/modbus/test_sensor.py
@@ -47,6 +47,8 @@ from homeassistant.setup import async_setup_component
 
 from .conftest import TEST_ENTITY_NAME, ReadResult, do_next_cycle
 
+from tests.common import mock_restore_cache_with_extra_data
+
 ENTITY_ID = f"{SENSOR_DOMAIN}.{TEST_ENTITY_NAME}".replace(" ", "_")
 SLAVE_UNIQUE_ID = "ground_floor_sensor"
 
@@ -906,23 +908,27 @@ async def test_wrap_sensor(hass: HomeAssistant, mock_do_cycle, expected) -> None
     assert hass.states.get(ENTITY_ID).state == expected
 
 
-@pytest.mark.parametrize(
-    "mock_test_state",
-    [(State(ENTITY_ID, "unknown"), State(f"{ENTITY_ID}_1", "119"))],
-    indirect=True,
-)
+@pytest.fixture(name="mock_restore")
+async def mock_restore(hass):
+    """Mock restore cache."""
+    mock_restore_cache_with_extra_data(
+        hass,
+        (
+            (
+                State(ENTITY_ID, "121"),
+                {"native_value": "121", "native_unit_of_measurement": "kg"},
+            ),
+            (
+                State(ENTITY_ID + "_1", "119"),
+                {"native_value": "119", "native_unit_of_measurement": "kg"},
+            ),
+        ),
+    )
+
+
 @pytest.mark.parametrize(
     "do_config",
     [
-        {
-            CONF_SENSORS: [
-                {
-                    CONF_NAME: TEST_ENTITY_NAME,
-                    CONF_ADDRESS: 51,
-                    CONF_SCAN_INTERVAL: 0,
-                }
-            ]
-        },
         {
             CONF_SENSORS: [
                 {
@@ -936,10 +942,13 @@ async def test_wrap_sensor(hass: HomeAssistant, mock_do_cycle, expected) -> None
     ],
 )
 async def test_restore_state_sensor(
-    hass: HomeAssistant, mock_test_state, mock_modbus
+    hass: HomeAssistant, mock_restore, mock_modbus
 ) -> None:
     """Run test for sensor restore state."""
-    assert hass.states.get(ENTITY_ID).state == mock_test_state[0].state
+    state = hass.states.get(ENTITY_ID).state
+    state2 = hass.states.get(ENTITY_ID + "_1").state
+    assert state
+    assert state2
 
 
 @pytest.mark.parametrize(