Service Interaction Protocol
Read Data By Identifier
0x22Protocol Identifier
The standard service for requesting data values from the ECU using 16-bit Data Identifiers (DIDs).
Overview
ISO 14229-1
“The client uses this service to request data record values from the server by one or more data identifiers.”
Unlike services with Sub-Functions (like 0x10 or 0x19), this service relies entirely on Data Identifiers (DIDs) to define the data content.
Message Structure
Request (0x22)
22DID1_HiDID1_Lo[DID2…]
Requests can contain multiple 2-byte DIDs.
Response (0x62)
62DID1_HiDID1_LoDATA…DID2…
DIDs are echoed back before their respective data.
Common Data Identifiers (DIDs)
Range | Category | Examples |
|---|---|---|
| 0xF180 - 0xF19F | Identification | VIN (0xF190), ECU Serial (0xF18C) |
| 0xF1A0 - 0xF1EF | Identification | Active Session (0xF186) |
| 0x0100 - 0xEFFF | Vehicle Mfr | RPM, Speed, Temperatures, Torques |
| 0xF200 - 0xF2FF | Periodic | Grouped data for periodic transmission |
| 0xFA00 - 0xFEFF | System Specific | Development & Calibration data |
Lookup Logic
A single request can contain multiple DIDs. The ECU processes each identifier, fetches the data from the internal mapping engine, and concatenates the results in the response.
Click to Enlarge
How the ECU resolves 16-bit identifiers to internal memory locations.
Example 1: Read VIN (0xF190)
tx_packet
Request
22 F1 90> Get Vehicle Identification Number
rx_packet
Response
62 F1 90 31 42 41...> Returns '1BA...' (ASCII Encoded)
Example 2: Multiple Identifiers
tx_packet
Request
22 12 34 56 78> Read DID 0x1234 AND 0x5678
rx_packet
Response
62 12 34 [Data1] 56 78 [Data2]> DIDs are interleaved with their data
Negative Response Codes
Logic_Exceptions
Critical_Error_Paths
NRC_0x13
Incorrect Message Length
Length is invalid (e.g. sent 0x22 F1 - missing low byte).
SEQ_DIAGRAM_DUMPOFFSET_0x7F
Incorrect Message Length Flow
2 stepsTester
ECU
NRC_0x31
Request Out Of Range
The requested DID is not supported by this ECU.
SEQ_DIAGRAM_DUMPOFFSET_0x7F
Request Out Of Range Flow
2 stepsTester
ECU
NRC_0x33
Security Access Denied
Attempted to read secured data without unlocking.
SEQ_DIAGRAM_DUMPOFFSET_0x7F
Security Access Denied Flow
2 stepsTester
ECU