UDS - Understanding ISO-TP Frames

Learn the structure of an ISO-TP frame and how to interact with modules using UDS.
Check us out at: blockharbor.io
UDS Services: [en.wikipedia.o...](en.wikipedia.o...)
Commands:
candump can0 | grep “ID1\|ID2”
isotprecv -p 00 -s ID1 -d ID2 -l can0
echo “22 f1 90” -p 00 -s ID1 -d ID2 can0
To learn more, check out our playlist of other car-hacking videos. • Getting Started in Aut...

[@SleipnirKang]

I am getting myself familiar with UDS and isotp. This is the most practical and detailed video I've seen right now. I really appreciate.

[@blockharbor]

I'm glad you like it! If you want to get hands-on and take The Plunge, we have the Hackathon 101 course for free or the Vehicle Penetration Testing course at vsec.blockharbor.io

[@plvlong]

Hi man, the video is supppper good for me, I am researching about COM STACK and Im stucking at How CANTP break down the date > 8byte. It's supper clear for me. Thanks alots

[@asikuttan]

This video is simple, but yet the best explanation on ISOTP. Thank you and keep up the good work :)

[@aenubiis]

What if 10:50 my theorical message lenght is 03E, and my actual message length is 67 bytes (3 + 8*8 bytes) ? Are there other parts that are unimportant in the message, therefore not counted ?

[@sshrek1996]

10:48 - In the first frame of the sequence the length of the data is 0x01B which is 27 in decimal, but the length of the VIN is 24-Bytes (33 46 4D 54 4B ...... 00 00 00 00 00). Can you help me with this?

[@blockharbor]

While the length of the VIN is 24 bytes, the entire message is 27 bytes of data. The length of the response includes the "62 F1 90," indicating a positive response to a service 22 requesting the VIN.

[@thechallenger3020]

Always the length of the Response = Length of Data + Service ID + Sub Service ID + ID
In the case:
Length of Data = 24 Bytes
Service ID = 1 Byte (0x22 + 0x40 = 0x62)
Sub Service ID = 0 (No Sub Service ID in Read DID)
ID = 2 Bytes (F1 90)
Total = 27 Bytes