Unified Diagnostic Services (UDS) — ISO 14229

Unified Diagnostic Services (UDS) is a communication protocol defined by the ISO 14229 standard, widely used in the automotive industry to enable diagnostic communication between an external test equipment (client) and the electronic control units (ECUs) embedded in a vehicle (server).

UDS operates on top of transport protocols such as CAN, DoIP (Diagnostics over IP), or FlexRay, and provides a standardized set of services for tasks like reading and clearing diagnostic trouble codes (DTCs), accessing ECU data by identifier, controlling I/O, uploading or downloading data, and managing diagnostic sessions and security access.

In the vast majority of cases, UDS is used over CAN (Controller Area Network). However, a standard CAN frame is limited to 8 bytes of payload, which is often insufficient for UDS messages. To overcome this limitation, the transport protocol is used as an intermediate layer between CAN and UDS. ISO-TP handles segmentation and reassembly of messages: when a UDS message exceeds 8 bytes, ISO-TP splits it into multiple CAN frames (First Frame, followed by Consecutive Frames), and uses Flow Control frames to manage the transmission rate between sender and receiver. For messages that fit within a single CAN frame, ISO-TP uses a Single Frame with a one-byte header indicating the payload length.

Communication follows a request-response model: the client sends a request message identified by a Service ID (SID), and the server replies with either a positive response (SID + 0x40) containing the requested data, or a negative response (0x7F) with a Negative Response Code (NRC) indicating the reason for failure.

The following section documents each UDS service with its request and response parameters, possible values, and supported NRCs.

Services

DiagnosticSessionControl (0x10)

The DiagnosticSessionControl service Used to change diagnostic sessions in the server(s). In each diagnostic session a different set of diagnostic services and/or functionalities is enabled in the server. The default session is always active after power-on or reset.

NRCs:

0x12

0x13

0x22

Request

Len (bits)
Parameter description
Value(hex)
8
DiagnosticSessionControl SID
0x10
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. If set to 1, the server shall not send a positive response message.
7
diagnosticSessionTypeSub-function parameter used to select the specific diagnostic session behavior of the server.

Positive response

Len (bits)
Parameter description
Value(hex)
8
DiagnosticSessionControl SID
0x50
1
Echo of suppressPosRspMsgIndicationBit
7
Echo of diagnosticSessionType
16
P2Server_maxMaximum time (in ms) the server requires to start with the response message after the reception of a request message.
0x0000-0xFFFF
16
P2StarServer_maxMaximum time (in ms, 10 ms resolution) the server requires to start with the response message after the transmission of a negative response with NRC 0x78 (requestCorrectlyReceivedResponsePending).
0x0000-0xFFFF

ECUReset (0x11)

The ECUReset service Used by the client to request that the server perform a reset of the ECU. The server performs the specified type of reset after sending the positive response.

NRCs:

0x12

0x13

0x22

0x33

Request

Len (bits)
Parameter description
Value(hex)
8
ECUReset SID
0x11
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. If set to 1, the server shall not send a positive response message.
7
resetTypeSub-function parameter that defines the type of reset to be performed by the server.

Positive response

Len (bits)
Parameter description
Value(hex)
8
ECUReset SID
0x51
1
Echo of suppressPosRspMsgIndicationBit
7
Echo of resetType
8
powerDownTimeTime (in seconds) the server requires to complete the power down sequence. Only present when resetType is enableRapidPowerShutDown (0x04). Value 0xFF means the time is not available.Optional
0x00-0xFF

ClearDiagnosticInformation (0x14)

The ClearDiagnosticInformation service Used by the client to clear Diagnostic Trouble Codes (DTCs) and all related diagnostic data stored in the server. This service has no sub-function parameter, so the suppressPosRspMsgIndicationBit is not available.

NRCs:

0x13

0x22

0x31

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
ClearDiagnosticInformation SID
0x14
24
groupOfDTCDefines the group of Diagnostic Trouble Codes that shall be cleared by the server. A 3-byte value identifying the DTC group (diagnostic domain) or all DTCs.
8
MemorySelectionSelects a specific DTC memory from which diagnostic information shall be cleared. Optional parameter introduced in ISO 14229-1:2020.Optional
0x00-0xFF

Positive response

Len (bits)
Parameter description
Value(hex)
8
ClearDiagnosticInformation SID
0x54

ReadDTCInformation (0x19)

The ReadDTCInformation service Enables the client to retrieve Diagnostic Trouble Code (DTC) information from one or more servers. The reportType sub-function determines the type of DTC data returned.

NRCs:

0x12

0x13

0x31

Request

Len (bits)
Parameter description
Value(hex)
8
ReadDTCInformation SID
0x19
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Retrieves the count of DTCs matching the given status mask.
0x01
8
DTCStatusMaskSpecifies which DTC status bits shall be used to filter matching DTCs.
0x00-0xFF

Positive response

Len (bits)
Parameter description
Value(hex)
8
ReadDTCInformation SID
0x59
1
Echo of suppressPosRspMsgIndicationBit
7
Retrieves the count of DTCs matching the given status mask.
0x01
8
DTCStatusAvailabilityMaskIndicates which DTC status bits are supported by the server.
0x00-0xFF
8
DTCFormatIdentifierIdentifies the DTC format used by the server when encoding Diagnostic Trouble Codes.
16
DTCCountNumber of stored DTCs that match the requested status mask criteria.
0x0000-0xFFFF

n = Number of DTC records

m = Number of DID/data pairs in snapshot record

ReadDataByIdentifier (0x22)

The ReadDataByIdentifier service Allows the client to retrieve data values associated with one or more Data Identifiers (DIDs) from the server.

NRCs:

0x12

0x13

0x31

Request

Len (bits)
Parameter description
Value(hex)
8
ReadDataByIdentifier SID
0x22
n*
16
dataIdentifierTwo-byte identifier specifying which data value to read from the server.
0x0000-0xFFFF

n = Number of data identifiers to read in a single request

Positive response

Len (bits)
Parameter description
Value(hex)
8
ReadDataByIdentifier SID
0x62
n*
16
dataIdentifierEchoed identifier indicating which data value follows.
0x0000-0xFFFF
99
dataRecordData value associated with the preceding data identifier.
0x0000000000000000000000000-0x8000000000000000000000000

n = Number of data identifier / data record pairs in the response

ReadMemoryByAddress (0x23)

The ReadMemoryByAddress service Allows the client to read a block of data from a specific memory location in the server.

NRCs:

0x13

0x22

0x31

Request

Len (bits)
Parameter description
Value(hex)
8
ReadMemoryByAddress SID
0x23
4
memorySizeLengthSpecifies the byte length of the memory size field.
0x0-0xF
4
memoryAddressLengthSpecifies the byte length of the memory address field.
0x0-0xF
n*
8
memoryAddressStarting address of the memory block to read.
0x00-0xFF
m*
8
memorySizeNumber of bytes to read from the specified memory address.
0x00-0xFF

n = value of memoryAddressLength

m = value of memorySizeLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
ReadMemoryByAddress SID
0x63
m*
8
dataRecordData bytes read from the specified memory location.
0x00-0xFF

m = Number of data bytes read from memory

SecurityAccess (0x27)

The SecurityAccess service Provides access to security-protected diagnostic services and data through a seed-and-key authentication mechanism.

NRCs:

0x12

0x13

0x22

0x24

0x31

0x35

0x36

0x37

Request

Len (bits)
Parameter description
Value(hex)
8
SecurityAccess SID
0x27
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Requests a challenge seed from the server (odd values are seed requests).
0x01
n*
8
securityAccessDataAdditional client identification data that the server verifies during the seed request.Optional
0x00-0xFF

n = Length of security access data (in bytes)

m = Length of security key (in bytes)

Positive response

Len (bits)
Parameter description
Value(hex)
8
SecurityAccess SID
0x67
1
Echo of suppressPosRspMsgIndicationBit
7
Requests a challenge seed from the server (odd values are seed requests).
0x01
n*
8
securitySeedChallenge value generated by the server, used by the client to compute the access key.
0x00-0xFF

n = Length of security seed (in bytes)

CommunicationControl (0x28)

The CommunicationControl service Allows the client to manage the communication behavior of the server by enabling or disabling specific message types on selected networks.

NRCs:

0x12

0x13

0x22

0x31

Request

Len (bits)
Parameter description
Value(hex)
8
CommunicationControl SID
0x28
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Re-enables both reception and transmission of messages.
0x00
4
networksIdentifies the sub-networks on which the communication control applies.
4
messageTypeIdentifies the category of messages to be controlled.

Positive response

Len (bits)
Parameter description
Value(hex)
8
CommunicationControl SID
0x68
1
Echo of suppressPosRspMsgIndicationBit
7
Re-enables both reception and transmission of messages.
0x00

ReadDataByPeriodicIdentifier (0x2A)

The ReadDataByPeriodicIdentifier service Allows the client to schedule periodic transmission of data identified by one or more periodic identifiers. The server sends data at the requested rate until instructed to stop.

NRCs:

0x13

0x22

0x31

0x33

Request

Len (bits)
Parameter description
Value(hex)
8
ReadDataByPeriodicIdentifier SID
0x2A
8
Starts periodic data transmission at a slow rate.
0x01
n*
8
periodicDataIdentifierSpecifies the identifier of the data to be periodically transmitted.
0x00-0xFF

n = Number of periodic data identifiers to schedule

Positive response

Len (bits)
Parameter description
Value(hex)
8
ReadDataByPeriodicIdentifier SID
0x6A

DynamicallyDefineDataIdentifier (0x2C)

The DynamicallyDefineDataIdentifier service Allows the client to create custom data identifiers by combining parts of existing identifiers or by referencing memory addresses.

NRCs:

0x12

0x13

0x22

0x31

0x33

Request

Len (bits)
Parameter description
Value(hex)
8
DynamicallyDefineDataIdentifier SID
0x2C
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Creates a dynamic identifier by combining portions of existing data identifiers.
0x01
16
dynamicallyDefinedDataIdentifierSpecifies the 2-byte identifier to assign to the new dynamic data definition.
0x0000-0xFFFF
n*
16
sourceDataIdentifierIdentifies the existing data source from which to extract data.
0x0000-0xFFFF
8
positionInSourceDataRecordByte position within the source data record where extraction begins.
0x00-0xFF
8
memorySizeNumber of bytes to extract from the source data record.
0x00-0xFF

n = Number of source DID groups to concatenate

m = value of memoryAddressLength

k = value of memorySizeLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
DynamicallyDefineDataIdentifier SID
0x6C
1
Echo of suppressPosRspMsgIndicationBit
7
Creates a dynamic identifier by combining portions of existing data identifiers.
0x01
16
Echo of dynamicallyDefinedDataIdentifier
0x0000-0xFFFF

WriteDataByIdentifier (0x2E)

The WriteDataByIdentifier service Allows the client to write a data value to a specific Data Identifier (DID) on the server.

NRCs:

0x13

0x21

0x31

0x33

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
WriteDataByIdentifier SID
0x2E
16
dataIdentifierTwo-byte identifier specifying the target data record to write.
0x0000-0xFFFF
n*
8
dataData bytes to write to the specified data identifier.
0x00-0xFF

n = Length of data to write (in bytes)

Positive response

Len (bits)
Parameter description
Value(hex)
8
WriteDataByIdentifier SID
0x6E
16
Echo of dataIdentifier
0x0000-0xFFFF

InputOutputControlByIdentifier (0x2F)

The InputOutputControlByIdentifier service Allows the client to control input/output signals of the server by specifying a Data Identifier and a control action.

NRCs:

0x13

0x22

0x31

0x33

Request

Len (bits)
Parameter description
Value(hex)
8
InputOutputControlByIdentifier SID
0x2F
16
dataIdentifierTwo-byte identifier of the I/O function to control.
0x0000-0xFFFF
8
Hands back control of the I/O function to the ECU.
0x00

n = Number of control state bytes

m = Number of control enable mask bytes

Positive response

Len (bits)
Parameter description
Value(hex)
8
InputOutputControlByIdentifier SID
0x6F
16
Echo of dataIdentifier
0x0000-0xFFFF
8
Hands back control of the I/O function to the ECU.
0x00
n*
8
controlStateCurrent state of the controlled I/O function.
0x00-0xFF

n = Number of control state bytes

RoutineControl (0x31)

The RoutineControl service Allows the client to start, stop, or request results of a server-side routine identified by a Routine Identifier (RID).

NRCs:

0x12

0x13

0x22

0x24

0x31

0x33

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
RoutineControl SID
0x31
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Initiates execution of the specified routine.
0x01
16
routineIdentifierTwo-byte identifier of the routine to control.
0x0000-0xFFFF
n*
8
routineControlOptionAdditional input parameters required by the routine.Optional
0x00-0xFF

n = Number of routine option bytes

Positive response

Len (bits)
Parameter description
Value(hex)
8
RoutineControl SID
0x71
1
Echo of suppressPosRspMsgIndicationBit
7
Initiates execution of the specified routine.
0x01
16
Echo of routineIdentifier
0x0000-0xFFFF
n*
8
routineStatusOutput data or status information returned by the routine.Optional
0x00-0xFF

n = Number of routine status bytes

RequestDownload (0x34)

The RequestDownload service Initiates a data download sequence by requesting the server to prepare for receiving data at the specified memory location.

NRCs:

0x13

0x22

0x31

0x33

0x70

Request

Len (bits)
Parameter description
Value(hex)
8
RequestDownload SID
0x34
4
compressionMethodSpecifies the compression algorithm applied to the data being transferred.
4
encryptingMethodSpecifies the encryption algorithm applied to the data being transferred.
4
memorySizeLengthSpecifies the byte length of the memory size field.
0x0-0xF
4
memoryAddressLengthSpecifies the byte length of the memory address field.
0x0-0xF
n*
8
memoryAddressTarget memory address where the downloaded data will be stored.
0x00-0xFF
m*
8
memorySizeTotal number of bytes to be downloaded.
0x00-0xFF

n = value of memoryAddressLength

m = value of memorySizeLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
RequestDownload SID
0x74
4
reserved
0x0-0xF
4
maxNumberOfBlockLengthBytesNumberNumber of bytes used to encode the maxNumberOfBlockLength value.
0x0-0xF
m*
8
maxNumberOfBlockLengthMaximum number of data bytes the server can receive per TransferData request.
0x00-0xFF

m = value of maxNumberOfBlockLengthBytesNumber

RequestUpload (0x35)

The RequestUpload service Initiates a data upload sequence by requesting the server to prepare for sending data from the specified memory location.

NRCs:

0x13

0x22

0x31

0x33

0x70

Request

Len (bits)
Parameter description
Value(hex)
8
RequestUpload SID
0x35
4
compressionMethodSpecifies the compression algorithm applied to the data being transferred.
4
encryptingMethodSpecifies the encryption algorithm applied to the data being transferred.
4
memorySizeLengthSpecifies the byte length of the memory size field.
0x0-0xF
4
memoryAddressLengthSpecifies the byte length of the memory address field.
0x0-0xF
n*
8
memoryAddressSource memory address from which data will be uploaded.
0x00-0xFF
m*
8
memorySizeTotal number of bytes to be uploaded.
0x00-0xFF

n = value of memoryAddressLength

m = value of memorySizeLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
RequestUpload SID
0x75
4
reserved
0x0-0xF
4
maxNumberOfBlockLengthBytesNumberNumber of bytes used to encode the maxNumberOfBlockLength value.
0x0-0xF
n*
8
maxNumberOfBlockLengthMaximum number of data bytes the server can send per TransferData response.
0x00-0xFF

n = value of maxNumberOfBlockLengthBytesNumber

TransferData (0x36)

The TransferData service Transfers data blocks between client and server during an active download or upload sequence initiated by RequestDownload or RequestUpload.

NRCs:

0x13

0x24

0x31

0x71

0x72

0x73

0x92

0x93

Request

Len (bits)
Parameter description
Value(hex)
8
TransferData SID
0x36
8
blockSequenceCounterSequence counter that increments with each TransferData message to ensure proper ordering.
0x00-0xFF
n*
8
transferRequestParameterData bytes sent by the client during a download sequence.Optional
0x00-0xFF

n = Number of transfer data bytes

Positive response

Len (bits)
Parameter description
Value(hex)
8
TransferData SID
0x76
8
Echo of blockSequenceCounter
0x00-0xFF
n*
8
transferResponseParameterData bytes returned by the server during an upload sequence.Optional
0x00-0xFF

n = Number of transfer response bytes

RequestTransferExit (0x37)

The RequestTransferExit service Terminates an active download or upload sequence previously initiated by RequestDownload or RequestUpload.

NRCs:

0x13

0x24

0x31

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
RequestTransferExit SID
0x37
n*
8
transferRequestParameterOptional completion data provided by the client (vehicle manufacturer specific).Optional
0x00-0xFF

n = Number of transfer request parameter bytes

Positive response

Len (bits)
Parameter description
Value(hex)
8
RequestTransferExit SID
0x77
n*
8
transferResponseParameterOptional status or result data returned by the server (vehicle manufacturer specific).Optional
0x00-0xFF

n = Number of transfer response parameter bytes

RequestFileTransfer (0x38)

The RequestFileTransfer service Allows the client to perform file system operations on the server, such as adding, deleting, replacing, reading, or resuming files and directories.

NRCs:

0x13

0x22

0x31

0x33

0x70

Request

Len (bits)
Parameter description
Value(hex)
8
RequestFileTransfer SID
0x38
8
Creates a new file on the server.
0x01
16
filePathAndNameLengthByte length of the filePathAndName field.
0x0000-0xFFFF
n*
8
filePathAndNameUTF-8 encoded path and name of the target file or directory.
0x00-0xFF
4
compressionMethodCompression algorithm applied to the file data.
4
encryptingMethodEncryption algorithm applied to the file data.
8
fileSizeParameterLengthByte length of each file size field (fileSizeUnCompressed and fileSizeCompressed).
0x00-0xFF
m*
8
fileSizeUnCompressedSize in bytes of the uncompressed file.
0x00-0xFF
m*
8
fileSizeCompressedSize in bytes of the compressed file.
0x00-0xFF

n = value of filePathAndNameLength

m = value of fileSizeParameterLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
RequestFileTransfer SID
0x78
8
Creates a new file on the server.
0x01
8
lengthFormatIdentifierByte length of the maxNumberOfBlockLength field.
0x00-0xFF
n*
8
maxNumberOfBlockLengthMaximum number of data bytes per TransferData message.
0x00-0xFF
4
compressionMethodCompression algorithm selected by the server.
4
encryptingMethodEncryption algorithm selected by the server.

n = value of lengthFormatIdentifier

m = value of fileSizeOrDirInfoParameterLength

WriteMemoryByAddress (0x3D)

The WriteMemoryByAddress service Allows the client to write a block of data to a specific memory location in the server.

NRCs:

0x13

0x22

0x31

0x33

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
WriteMemoryByAddress SID
0x3D
4
memorySizeLengthSpecifies the byte length of the memory size field.
0x0-0xF
4
memoryAddressLengthSpecifies the byte length of the memory address field.
0x0-0xF
n*
8
memoryAddressTarget memory address where data will be written.
0x00-0xFF
m*
8
memorySizeNumber of bytes to write at the specified address.
0x00-0xFF
k*
8
dataData bytes to write to memory.
0x00-0xFF

n = value of memoryAddressLength

m = value of memorySizeLength

k = Number of data bytes to write

Positive response

Len (bits)
Parameter description
Value(hex)
8
WriteMemoryByAddress SID
0x7D
4
Echo of memorySizeLength
0x0-0xF
4
Echo of memoryAddressLength
0x0-0xF
n*
8
memoryAddressTarget memory address where data will be written.
0x00-0xFF
m*
8
memorySizeNumber of bytes to write at the specified address.
0x00-0xFF

TesterPresent (0x3E)

The TesterPresent service Signals to the server that the diagnostic client is still connected, preventing the current session from timing out.

NRCs:

0x13

0x22

0x31

0x33

0x72

Request

Len (bits)
Parameter description
Value(hex)
8
TesterPresent SID
0x3E
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
zeroSubFunctionSub-function value fixed to zero (no additional behavior).

Positive response

Len (bits)
Parameter description
Value(hex)
8
TesterPresent SID
0x7E
1
Echo of suppressPosRspMsgIndicationBit
7
Echo of zeroSubFunction

SecuredDataTransmission (0x84)

The SecuredDataTransmission service Wraps any UDS service request in a secured envelope, providing encryption, signing, and anti-replay protection for sensitive diagnostic operations.

NRCs:

0x13

Request

Len (bits)
Parameter description
Value(hex)
8
SecuredDataTransmission SID
0x84
8
reservedReserved bits, fixed to zero.
1
reservedReserved bits, fixed to zero.
1
signatureRequestedIndicates whether the server should include a signature in the response.
1
isSignedIndicates whether this message includes a digital signature.
1
isEncryptedIndicates whether the payload of this message is encrypted.
1
preEstablishedKeyUsedIndicates whether a previously established encryption key is reused for this message.
2
reservedReserved bits, fixed to zero.
1
isRequestMessageIndicates this is a request message (always set to 1 for requests).
8
SignatureEncryptionCalculationIdentifies the cryptographic algorithms used for signing and encryption.
0x00-0xFF
16
signatureLengthByte length of the signature field appended to the message.
0x0000-0xFFFF
16
antiReplayCounterMonotonic counter value used to detect and prevent replay attacks.
0x0000-0xFFFF
8
internalMessageServiceRequestIDService Identifier (SID) of the UDS service being secured.
0x00-0xFF
n*
8
serviceSpecificParametersPayload bytes of the secured UDS service request.Optional
0x00-0xFF
m*
8
signatureDigital signature computed over the message content.Optional
0x00-0xFF

n = Number of service-specific parameter bytes

m = value of signatureLength

Positive response

Len (bits)
Parameter description
Value(hex)
8
SecuredDataTransmission SID
0xC4
8
reservedReserved bits, fixed to zero.
1
reservedReserved bits, fixed to zero.
1
signatureRequestedIndicates whether a signature was requested.
1
isSignedIndicates whether this response includes a digital signature.
1
isEncryptedIndicates whether the response payload is encrypted.
1
preEstablishedKeyUsedIndicates whether a previously established encryption key was used.
2
reservedReserved bits, fixed to zero.
1
isRequestMessageIndicates this is a response message (always set to 0 for responses).
8
SignatureEncryptionCalculationIdentifies the cryptographic algorithms used for signing and encryption.
0x00-0xFF
16
signatureLengthByte length of the signature field appended to the response.
0x0000-0xFFFF
16
antiReplayCounterMonotonic counter value for replay attack prevention.
0x0000-0xFFFF
8
internalMessageServiceResponseIDService Identifier (SID + 0x40) of the secured UDS service response.
0x00-0xFF
n*
8
serviceSpecificParametersPayload bytes of the secured UDS service response.Optional
0x00-0xFF
m*
8
signatureDigital signature computed over the response content.Optional
0x00-0xFF

n = Number of service-specific parameter bytes

m = value of signatureLength

ControlDTCSetting (0x85)

The ControlDTCSetting service Allows the client to instruct the server to stop or resume updating DTC status bits in its memory.

NRCs:

0x12

0x13

0x22

Request

Len (bits)
Parameter description
Value(hex)
8
ControlDTCSetting SID
0x85
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
DTCSettingTypeDetermines whether DTC status updating is enabled or disabled.
n*
8
DTCSettingControlOptionRecordOptional vehicle manufacturer specific control parameters.Optional
0x00-0xFF

n = Number of DTC setting control option bytes

Positive response

Len (bits)
Parameter description
Value(hex)
8
ControlDTCSetting SID
0xC5
1
Echo of suppressPosRspMsgIndicationBit
7
Echo of DTCSettingType

LinkControl (0x87)

The LinkControl service Allows the client to verify and switch the communication link baudrate between the client and the server.

NRCs:

0x12

0x13

0x22

0x24

0x31

Request

Len (bits)
Parameter description
Value(hex)
8
LinkControl SID
0x87
1
suppressPosRspMsgIndicationBitBit 7 of the sub-function byte. When set to 1, the server will not send a positive response.
7
Verifies the server can transition to a standard baudrate from a predefined list.
0x01
8
linkControlModeIdentifier

Positive response

Len (bits)
Parameter description
Value(hex)
8
LinkControl SID
0xC7
1
Echo of suppressPosRspMsgIndicationBit
7
Verifies the server can transition to a standard baudrate from a predefined list.
0x01