This part of ISO 9141 establishes recommended test methods, test procedures and specific test parameters in order to verify a vehicle or OBD II scan tool can communicate on a bus according to ISO 9141-2. It is not applicable as a test for a single module or for any subpart of an ISO 9141-2 network.

The test described is not provided to verify any tool or vehicle requirement not described in ISO 9141-2. In particular it does not check any requirement described in SAE J1962, SAE J1978, ISO 15031-5 or the expanded diagnostic protocol for scan tool.

The procedures and methods test a set of specific requirements applicable to all road vehicles and scan tools which make use of ISO 9141-2.