Security Access
0x27The Security Access service provides access to security-protected diagnostic services and data through a seed-and-key authentication mechanism.
✕Negative response codes
0x120x130x220x240x310x350x360x37
Request
SID 0x27 · 2 bytesLen (bits)
Parameter description
Value (hex)
8
Security Access SID0x271
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).
0x01n*
8
securityAccessDataAdditional client identification data that the server verifies during the seed request.Optional0x00-0xFFn = Length of security access data (in bytes)
m = Length of security key (in bytes)
Positive response
SID 0x67Len (bits)
Parameter description
Value (hex)
8
Security Access SID0x671
Echo of
suppressPosRspMsgIndicationBit7
Requests a challenge seed from the server (odd values are seed requests).
0x01n*
8
securitySeedChallenge value generated by the server, used by the client to compute the access key.0x00-0xFFn = Length of security seed (in bytes)