KWP 2000 on K-Line – ISO 14230

The KWP 2000 protocol (Keyword Protocol 2000) marked the emergence of the first widely adopted common standard among European automakers. Initially, the protocol was specified for the K-Line bus system. Today, this protocol is found only in older control units. ISO 14230 standardizes the KWP 2000 protocol for K-Line. The ISO standard also specifies the physical layer, including its requirements for diagnostic testers and ECUs; the datalink layer; and the application layer, which describes the communication model and diagnostic services; as well as the requirements for emissions-related systems.

Communication is based on requests and responses between the diagnostic tester and the ECUs. The request is initiated by the diagnostic tester. The services consist of the address information in the header, a Service Identifier (SID), and the parameters in the payload. In the event of a negative response, the payload consists of Error ID 0x7F, the Service ID, and an error code.

Functional unit	Diagnostic service name	Request SID	Response SID
Diagnostic Management	StartDiagnosticSession	0x10	0x50
	StopDiagnosticSession	0x20	0x60
	SecurityAccess	0x27	0x67
	TesterPresent	0x3E	0x7E
	ECUReset	0x11	0x51
	ReadECUIdentification	0x1A	0x5A
Data Transmission	ReadDataByLocalIdentifier	0x21	0x61
	ReadDataByCommonIdentifier	0x22	0x62
	ReadMemoryByAddress	0x23	0x63
	DynamicallyDefineLocalIdentifier	0x2C	0x6C
	WriteDataByLocalIdentifier	0x3B	0x7B
	WriteDataByCommonIdentifier	0x3E	0x6E
	WriteMemoryByAddress	0x3D	0x7D
	SetDataRates	0x26	0x66
Stored Data Transmission	ReadDiagnosticTroubleCodes	0x13	0x53
	ReadDiagnosticTroubleCodesByStatus	0x18	0x58
	ReadStatusOdDiagnosticTroubleCodes	0x17	0x57
	ReadFreezeFrameData	0x12	0x52
	ClearDiagnosticInformation	0x14	0x54
Input/Output Control	InputOutputControlByLocalIdentifier	0x30	0x70
	InputOutputControlByCommonIdentifier	0x2F	0x6F
Remove Activation or Routine	StartRoutineByLocalIdentifier	0x31	0x71
	StopRoutineByLocalIdentifier	0x32	0x72
	RequestRoutineResultsByLocalIdentifier	0x33	0x73
	StartRoutineByAddress	0x38	0x78
	StopRoutineByAddress	0x39	0x79
	RequestRoutineResultsByAddress	0x3A	0x7A
Upload/Download	RequestDownload	0x34	0x74
	RequestUpload	0x35	0x75
	TransferData	0x36	0x76
	RequestTransferExit	0x37	0x77