This SAE Recommended Practice defines diagnostic test modes, and request and response messages, necessary to be supported by vehicle manufacturers and test tools to meet the requirements of the California OBD II and Federal OBD regulations, which pertain to vehicle emission-related data only. These messages are intended to be used by any service tool capable of performing the mandated diagnostics. Diagnostic Test Modes included in this document are: For each test mode, this specification includes:
- a Functional descriptions of test mode
- b Request and response message formats
For some of the more complex test modes, an example of messages and an explanation of the interpretation of those messages is included.
