UDS – ISO 14229

The advent of new bus systems necessitated a protocol independent of them. Based on KWP 2000, the new UDS (Unified Diagnostic Services) protocol was developed and defined in ISO standard 14229. Among other changes, KWP 2000 services were regrouped and consolidated using a new parameter: the sub-function level. Furthermore, new functionalities were introduced, such as a security layer for encrypted services, event-driven service execution, and the suppression of positive responses from control units.

Since CAN is limited to 8 bytes of payload data, the implementation of UDS over CAN was additionally specified in ISO 15765-3.

Functional unit	Diagnostic service name	Request SID	Response SID
Diagnostic and Communication Management	DiagnosticSessionControl	0x10	0x50
	SecurityAccess	0x27	0x67
	TesterPresent	0x3E	0x7E
	ECUReset	0x11	0x51
	CommunicationControl	0x28	0x68
	AccessTimingParameter	0x83	0xC3
	SecuredDataTransmission	0x84	0xC4
	ControlDTCSetting	0x85	0xC5
	ResponseOnEvent	0x86	0xC6
	LinkControl	0x87	0xC7
Data Transmission	ReadDataByIdentifier	0x22	0x62
	ReadMemoryByAddress	0x23	0x63
	ReadScalingDataByIdentifier	0x24	0x64
	ReadDataByPeriodicIdentifier	0x2A	0x6A
	DynamicallyDefineDataIdentifier	0x2C	0x6C
	WriteDataByIdentifier	0x3E	0x6E
	WriteMemoryByAddress	0x3D	0x7D
Stored Data Transmission	ReadDTCInformation	0x19	0x59
	ClearDiagnosticInformation	0x14	0x54
Input/Output Control	InputOutputControlByIdentifier	0x2F	0x6F
Remove Activation or Routine	StartRoutineByLocalIdentifier	0x31	0x71
Upload/Download	RequestDownload	0x34	0x74
	RequestUpload	0x35	0x75
	TransferData	0x36	0x76
	RequestTransferExit	0x37	0x77
	RequestFileTransfer	0x38	0x78