UDS Services

This page documents the services supported by iso14229.

Supported Services

Service ID	Service Name	Server	Client	Standard Responses*
0x10	Diagnostic Session Control	Y	Y	NRCs
0x11	ECU Reset	Y	Y	NRCs
0x14	Clear Diagnostic Information	Y	N	NRCs
0x19	Read DTC Information	N	N
0x22	Read Data By Identifier	Y	Y	NRCs
0x23	Read Memory By Address	N	N
0x24	Read Scaling Data By Identifier	N	N
0x27	Security Access	Y	Y	NRCs
0x28	Communication Control	Y	Y	NRCs
0x2A	Read Periodic Data By Identifier	N	N
0x2C	Dynamically Define Data Identifier	N	N
0x2E	Write Data By Identifier	Y	Y	NRCs
0x2F	Input/Output Control By Identifier	Y	N
0x31	Routine Control	Y	Y	NRCs
0x34	Request Download	Y	Y	NRCs
0x35	Request Upload	Y	Y
0x36	Transfer Data	Y	Y	NRCs
0x37	Request Transfer Exit	Y	Y	NRCs
0x38	Request File Transfer	Y	Y
0x3D	Write Memory By Address	Y	N
0x3E	Tester Present	Y	Y
0x83	Access Timing Parameter	N	N
0x84	Secured Data Transmission	N	N
0x85	Control DTC Setting	Y	Y
0x86	Response On Event	N	N
0x87	Link Control	Y	N

Standard Responses*

The standard lists a set of supported NRCs for each service. In your server implementation, it is recommended to use to these whenever possible.

---

0x10 Diagnostic Session Control

Change the diagnostic session type.

Server Event

UDS_EVT_DiagSessCtrl

Arguments

typedef struct {
    const uint8_t type;  /*! requested session type */
    uint16_t p2_ms;      /*! optional return value: p2 timing override */
    uint32_t p2_star_ms; /*! optional return value: p2* timing override */
} UDSDiagSessCtrlArgs_t;

Session Types

Value	Define	Description
0x01	UDS_LEV_DS_DS	Default Session
0x02	UDS_LEV_DS_PRGS	Programming Session
0x03	UDS_LEV_DS_EXTDS	Extended Diagnostic Session
0x04	UDS_LEV_DS_SSDS	Safety System Diagnostic Session

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Request accepted
0x12	UDS_NRC_SubFunctionNotSupported	Requested session type not supported
0x22	UDS_NRC_ConditionsNotCorrect	Conditions not correct

Client API

UDSSendDiagSessCtrl

---

0x11 ECU Reset

Request ECU reset.

Server Event

UDS_EVT_EcuReset

Arguments

typedef struct {
    const uint8_t type;           /*! reset type */
    uint32_t powerDownTimeMillis; /*! delay before reset event */
} UDSECUResetArgs_t;

Reset Types

Value	Define	Description
0x01	UDS_LEV_RT_HR	Hard Reset
0x02	UDS_LEV_RT_KOFFONR	Key Off On Reset
0x03	UDS_LEV_RT_SR	Soft Reset
0x04	UDS_LEV_RT_ERPSD	Enable Rapid Power Shutdown
0x05	UDS_LEV_RT_DRPSD	Disable Rapid Power Shutdown

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Reset will occur
0x12	UDS_NRC_SubFunctionNotSupported	Reset type not supported
0x22	UDS_NRC_ConditionsNotCorrect	Conditions not correct for reset
0x33	UDS_NRC_SecurityAccessDenied	Security access required

Client API

UDSSendECUReset

---

0x14 Clear Diagnostic Information

Clear diagnostic trouble codes.

Server Event

UDS_EVT_ClearDiagnosticInfo

Arguments

typedef struct {
    const uint32_t groupOfDTC;     /*! DTC group to clear */
    const bool hasMemorySelection; /*! memory selection present */
    const uint8_t memorySelection; /*! memory selection (optional) */
} UDSCDIArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	DTCs cleared
0x22	UDS_NRC_ConditionsNotCorrect	Cannot clear DTCs now
0x31	UDS_NRC_RequestOutOfRange	Invalid DTC group

---

0x22 Read Data By Identifier

Read data identified by a 16-bit identifier.

Server Event

UDS_EVT_ReadDataByIdent

Arguments

typedef struct {
    const uint16_t dataId; /*! data identifier */
    uint8_t (*copy)(UDSServer_t *srv, const void *src, uint16_t count);
} UDSRDBIArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Data returned successfully
0x14	UDS_NRC_ResponseTooLong	Response exceeds buffer
0x22	UDS_NRC_ConditionsNotCorrect	Cannot read data now
0x31	UDS_NRC_RequestOutOfRange	Data identifier not supported
0x33	UDS_NRC_SecurityAccessDenied	Security access required

Client API

UDSSendRDBI, UDSUnpackRDBIResponse

Example

See Read/Write Data By Identifier Example

---

0x27 Security Access

Unlock security-protected diagnostic services.

Server Events

• UDS_EVT_SecAccessRequestSeed - Client requests seed
• UDS_EVT_SecAccessValidateKey - Client sends key for validation

Arguments

Request Seed:

typedef struct {
    const uint8_t level;             /*! security level */
    const uint8_t *const dataRecord; /*! request data */
    const uint16_t len;              /*! data length */
    uint8_t (*copySeed)(UDSServer_t *srv, const void *src, uint16_t len);
} UDSSecAccessRequestSeedArgs_t;

Validate Key:

typedef struct {
    const uint8_t level;      /*! security level */
    const uint8_t *const key; /*! key to validate */
    const uint16_t len;       /*! key length */
} UDSSecAccessValidateKeyArgs_t;

Security Levels

Odd levels (0x01, 0x03, ...) request seed, even levels (0x02, 0x04, ...) send key.

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Seed provided or key accepted
0x12	UDS_NRC_SubFunctionNotSupported	Security level not supported
0x22	UDS_NRC_ConditionsNotCorrect	Wrong sequence
0x24	UDS_NRC_RequestSequenceError	Request out of sequence
0x35	UDS_NRC_InvalidKey	Key verification failed
0x36	UDS_NRC_ExceedNumberOfAttempts	Too many failed attempts
0x37	UDS_NRC_RequiredTimeDelayNotExpired	Must wait before retry

Client API

UDSSendSecurityAccess, UDSUnpackSecurityAccessResponse

Example

See Security Access Example (0x27)

---

0x28 Communication Control

Control communication messages.

Server Event

UDS_EVT_CommCtrl

Arguments

typedef struct {
    uint8_t ctrlType; /*! control type */
    uint8_t commType; /*! communication type */
    uint16_t nodeId;  /*! node ID (optional) */
} UDSCommCtrlArgs_t;

Control Types

Value	Define	Description
0x00	UDS_LEV_CTRLTP_ERXTX	Enable RX and TX
0x01	UDS_LEV_CTRLTP_ERXDTX	Enable RX, Disable TX
0x02	UDS_LEV_CTRLTP_DRXETX	Disable RX, Enable TX
0x03	UDS_LEV_CTRLTP_DRXTX	Disable RX and TX

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Control accepted
0x12	UDS_NRC_SubFunctionNotSupported	Control type not supported
0x22	UDS_NRC_ConditionsNotCorrect	Cannot apply control
0x31	UDS_NRC_RequestOutOfRange	Invalid parameters

Client API

UDSSendCommCtrl

---

0x2E Write Data By Identifier

Write data identified by a 16-bit identifier.

Server Event

UDS_EVT_WriteDataByIdent

Arguments

typedef struct {
    const uint16_t dataId;     /*! data identifier */
    const uint8_t *const data; /*! data to write */
    const uint16_t len;        /*! data length */
} UDSWDBIArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Data written successfully
0x13	UDS_NRC_IncorrectMessageLengthOrInvalidFormat	Invalid data length
0x22	UDS_NRC_ConditionsNotCorrect	Cannot write now
0x31	UDS_NRC_RequestOutOfRange	Data identifier not supported
0x33	UDS_NRC_SecurityAccessDenied	Security access required

Client API

UDSSendWDBI

Example

See Read/Write Data By Identifier Example

---

0x31 Routine Control

Start, stop, or request results from server-side routines.

Server Event

UDS_EVT_RoutineCtrl

Arguments

typedef struct {
    const uint8_t ctrlType;      /*! routine control type */
    const uint16_t id;           /*! routine identifier */
    const uint8_t *optionRecord; /*! optional data */
    const uint16_t len;          /*! option data length */
    uint8_t (*copyStatusRecord)(UDSServer_t *srv, const void *src, uint16_t len);
} UDSRoutineCtrlArgs_t;

Control Types

Value	Define	Description
0x01	UDS_LEV_RCTP_STR	Start Routine
0x02	UDS_LEV_RCTP_STPR	Stop Routine
0x03	UDS_LEV_RCTP_RRR	Request Routine Results

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Routine control accepted
0x12	UDS_NRC_SubFunctionNotSupported	Control type not supported
0x22	UDS_NRC_ConditionsNotCorrect	Cannot execute routine
0x24	UDS_NRC_RequestSequenceError	Wrong sequence
0x31	UDS_NRC_RequestOutOfRange	Routine ID not supported
0x33	UDS_NRC_SecurityAccessDenied	Security access required

Client API

UDSSendRoutineCtrl, UDSUnpackRoutineControlResponse

---

0x34 Request Download

Initiate data download to server (flash programming, calibration update).

Server Event

UDS_EVT_RequestDownload

Arguments

typedef struct {
    const void *addr;                   /*! memory address */
    const size_t size;                  /*! download size */
    const uint8_t dataFormatIdentifier; /*! data format */
    uint16_t maxNumberOfBlockLength;    /*! max block size response */
} UDSRequestDownloadArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Download accepted
0x22	UDS_NRC_ConditionsNotCorrect	Cannot download now
0x31	UDS_NRC_RequestOutOfRange	Invalid address/size
0x33	UDS_NRC_SecurityAccessDenied	Security access required
0x70	UDS_NRC_UploadDownloadNotAccepted	Download rejected

Client API

UDSSendRequestDownload, UDSUnpackRequestDownloadResponse

---

0x36 Transfer Data

Transfer data blocks after Request Download/Upload.

Server Event

UDS_EVT_TransferData

Arguments

typedef struct {
    const uint8_t *const data; /*! transfer data */
    const uint16_t len;        /*! data length */
    const uint16_t maxRespLen; /*! max response length */
    uint8_t (*copyResponse)(UDSServer_t *srv, const void *src, uint16_t len);
} UDSTransferDataArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Data transferred
0x24	UDS_NRC_RequestSequenceError	No active transfer
0x71	UDS_NRC_TransferDataSuspended	Transfer suspended
0x72	UDS_NRC_GeneralProgrammingFailure	Programming failed
0x73	UDS_NRC_WrongBlockSequenceCounter	Block sequence error

Client API

UDSSendTransferData

---

0x37 Request Transfer Exit

Terminate data transfer.

Server Event

UDS_EVT_RequestTransferExit

Arguments

typedef struct {
    const uint8_t *const data; /*! request data */
    const uint16_t len;        /*! data length */
    uint8_t (*copyResponse)(UDSServer_t *srv, const void *src, uint16_t len);
} UDSRequestTransferExitArgs_t;

Supported Responses

Value	Enum	Meaning
0x00	UDS_PositiveResponse	Transfer exited successfully
0x24	UDS_NRC_RequestSequenceError	No active transfer
0x72	UDS_NRC_GeneralProgrammingFailure	Exit processing failed

Client API

UDSSendRequestTransferExit

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See Also

• Client API
• Server API
• ISO 14229-1:2020 - Road vehicles - Unified diagnostic services (UDS)