Automotive Diagnostics — Access Timing Parameter

Use this advanced service if you want to change any communication parameters. Generally, this is optionally implemented in the server/ECU because the timing parameters would not be exposed to the outside world. Implementation of the service depends on the designer to change any communication parameters or configuration.

To use the following service, the below sequence is recommended –

• Extended Diagnostic Session Control service
• Read AccessTimingParameter service
• Set AccessTimingParameter service

Subfunctions supported by Access timing parameters are

Important points about access timing parameters are

• The server/ECU sends a positive response to the service and then process the change of communication timing parameter updates
• The server/ECU and client/tester would reset themselves back to default parameters once the diagnostic session control expires from the non-default session

Examples for message flow

Consider a scenario where the default parameters need to be set by the Access timing parameter service

Request message

Positive response message

Negative response message

Supported Negative response codes: