This document summarizes the CAN transport layer frame format for the Unified Diagnostic Services (UDS) protocol. It explains that UDS frames begin with a header containing a service identifier (SID) and length, followed by a data portion containing parameters linked to the diagnostic identifier (DID). The document provides examples of single frame requests and responses, as well as multi-frame transmissions where data is split across multiple frames. It concludes by inviting questions about CAN transport protocol and UDS.

1. CAN Transport
Layer - UDS Frame
By Kapil Thakar
0x03 0x22 0xF1 0x20
0x10 0x0B 0x62 0xF1 0x20 0x01 0x02 0x03
Initial 3 Bytes of Data linked with DIDDID
Length
SID+
40

2. Frame Types

3. Examples:
Single Frame Request / Response:
Request: 0x02 0x10 0x03 – Request for Extended Session
Response: 0x06 0x50 0x03 0xAA 0xBB 0xCC 0xDD (Total 7 bytes)
0x02 0x10 0x03
0x06 0x50 0x03 0xAA 0xBB 0xCC 0xDD
Requested Data 4 Bytes linked with DID
P2 server time: 0xAA 0xBB
P2* server time: 0xCC 0xDD
SID+
40
Length
SFIndicator
SubFunction

4. Examples:
Single Frame Request / Response:
Request 0x03 0x22 0xF2 0x00
Response: 0x04 0x62 0xF2 0x00 0x01
0x03 0x22 0xF2 0x00
0x06 0x62 0xF2 0x00 0x01 0x02 0x03
Requested Data 3 Bytes linked with DID
SID+
40
Length
SFIndicator
DID

5. Examples:
Single Frame Request / Multiple Response:
Request: 0x03 0x22 0xF1 0x20
Response: 0x10 0x0B 0x62 0xF1 0x20 0x01 0x02 0x03
Tester : 0x30 0x00 0x00
ECU: 0x04 0x05 0x06 0x07 0x08
0x03 0x22 0xF1 0x20
0x10 0x0B 0x62 0xF1 0x20 0x01 0x02 0x03
Initial 3 Bytes of Data linked with DIDDID
Length
FFIndicator
SID+
40

6. Examples:
Multi Frame Request / Response:
Request: 0x03 0x22 0xF1 0x20
Response: 0x10 0x0B 0x62 0xF1 0x20 0x01 0x02 0x03
Tester : 0x30 0x00 0x00
ECU: 0x04 0x05 0x06 0x07 0x08
0x30 0x00 0x00
0x21 0x04 0x05 0x06 0x07 0x08
Remaining 5 Data Bytes of Data linked with DID
CCFIndicator
Sequenceno
FCIndicator
FlowStatus
BlockSize
Separation
TimeMinimum

7. CAN TP / UDS
Questions ?