diff --git a/odxtools/dtcdop.py b/odxtools/dtcdop.py
index 39bca96a..979be3aa 100644
--- a/odxtools/dtcdop.py
+++ b/odxtools/dtcdop.py
@@ -137,13 +137,17 @@ def convert_physical_to_bytes(self, physical_value: ParameterValue, encode_state
             trouble_code = physical_value
         elif isinstance(physical_value, str):
             # assume that physical value is the short_name
-            dtc = next(filter(lambda dtc: dtc.short_name == physical_value, self.dtcs))
-            trouble_code = dtc.trouble_code
+            dtcs = [dtc for dtc in self.dtcs if dtc.short_name == physical_value]
+            odxassert(len(dtcs) == 1)
+            trouble_code = dtcs[0].trouble_code
         else:
             raise EncodeError(f"The DTC-DOP {self.short_name} expected a"
                               f" DiagnosticTroubleCode but got {physical_value!r}.")
 
-        return super().convert_physical_to_bytes(trouble_code, encode_state, bit_position)
+        internal_trouble_code = self.compu_method.convert_physical_to_internal(trouble_code)
+
+        return self.diag_coded_type.convert_internal_to_bytes(
+            internal_trouble_code, encode_state=encode_state, bit_position=bit_position)
 
     def _build_odxlinks(self) -> Dict[OdxLinkId, Any]:
         odxlinks = super()._build_odxlinks()
diff --git a/odxtools/parameters/physicalconstantparameter.py b/odxtools/parameters/physicalconstantparameter.py
index e54184ad..6a5387b3 100644
--- a/odxtools/parameters/physicalconstantparameter.py
+++ b/odxtools/parameters/physicalconstantparameter.py
@@ -1,5 +1,4 @@
 # SPDX-License-Identifier: MIT
-import warnings
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Dict
 
@@ -70,13 +69,10 @@ def decode_from_pdu(self, decode_state: DecodeState) -> ParameterValue:
 
         # Check if decoded value matches expected value
         if phys_val != self.physical_constant_value:
-            warnings.warn(
+            odxraise(
                 f"Physical constant parameter does not match! "
                 f"The parameter {self.short_name} expected physical value "
                 f"{self.physical_constant_value!r} but got {phys_val!r} "
                 f"at byte position {decode_state.cursor_byte_position} "
-                f"in coded message {decode_state.coded_message.hex()}.",
-                DecodeError,
-                stacklevel=1,
-            )
+                f"in coded message {decode_state.coded_message.hex()}.", DecodeError)
         return phys_val
diff --git a/odxtools/parameters/valueparameter.py b/odxtools/parameters/valueparameter.py
index 8c0fad88..ecfb7196 100644
--- a/odxtools/parameters/valueparameter.py
+++ b/odxtools/parameters/valueparameter.py
@@ -18,6 +18,9 @@
 class ValueParameter(ParameterWithDOP):
     physical_default_value_raw: Optional[str]
 
+    def __post_init__(self) -> None:
+        self._physical_default_value: Optional[AtomicOdxType] = None
+
     @property
     def parameter_type(self) -> ParameterType:
         return "VALUE"
@@ -31,7 +34,6 @@ def _resolve_odxlinks(self, odxlinks: OdxLinkDatabase) -> None:
     def _resolve_snrefs(self, diag_layer: "DiagLayer") -> None:
         super()._resolve_snrefs(diag_layer)
 
-        self._physical_default_value: Optional[AtomicOdxType] = None
         if self.physical_default_value_raw is not None:
             dop = odxrequire(self.dop)
             if not isinstance(dop, DataObjectProperty):
diff --git a/tests/test_decoding.py b/tests/test_decoding.py
index f3783905..62df2ace 100644
--- a/tests/test_decoding.py
+++ b/tests/test_decoding.py
@@ -21,7 +21,7 @@
 from odxtools.minmaxlengthtype import MinMaxLengthType
 from odxtools.nameditemlist import NamedItemList
 from odxtools.odxlink import OdxDocFragment, OdxLinkDatabase, OdxLinkId, OdxLinkRef
-from odxtools.odxtypes import DataType
+from odxtools.odxtypes import DataType, ParameterValueDict
 from odxtools.parameters.codedconstparameter import CodedConstParameter
 from odxtools.parameters.matchingrequestparameter import MatchingRequestParameter
 from odxtools.parameters.physicalconstantparameter import PhysicalConstantParameter
@@ -1478,7 +1478,7 @@ def test_decode_response(self) -> None:
             self.assertEqual(expected_message.coding_object, decoded_message.coding_object)
             self.assertEqual(expected_message.param_dict, decoded_message.param_dict)
 
-    def test_decode_dtc(self) -> None:
+    def test_code_dtc(self) -> None:
         odxlinks = OdxLinkDatabase()
         diag_coded_type = StandardLengthType(
             base_data_type=DataType.A_UINT32,
@@ -1570,9 +1570,14 @@ def test_decode_dtc(self) -> None:
         dop._resolve_odxlinks(odxlinks)
         pos_response._resolve_odxlinks(odxlinks)
 
-        coded_message = bytes([0x12, 0x34])
-        decoded_param_dict = pos_response.decode(coded_message)
-        self.assertEqual(decoded_param_dict["DTC_Param"], dtc1)
+        expected_coded_message = bytes([0x12, 0x34])
+        expected_param_dict: ParameterValueDict = {"SID": 0x12, "DTC_Param": dtc1}
+
+        actual_param_dict = pos_response.decode(expected_coded_message)
+        self.assertEqual(actual_param_dict, expected_param_dict)
+
+        actual_coded_message = pos_response.encode(coded_request=None, **expected_param_dict)
+        self.assertEqual(actual_coded_message, expected_coded_message)
 
 
 class TestDecodingAndEncoding(unittest.TestCase):