Diagnostics Systems Applications


OTX (Open Test Sequence eXchange, ISO 13209) is an international standard for the formal description of diagnostic and test sequences in the automotive industry. Thereby, it complements the ODX format used to exchange diagnostic data.

The OTX format is relevant to the areas of development, production and service by enabling the exchange of diagnostic procedures between process partners with different platforms and diagnostic testers. Thus, procedures can easily be reused and extended if necessary.

With the sequence language OTX, diagnostic sequences can be displayed both at the specification level and at the same time contain enough implementation details so that they can also be performed. Moreover, OTX directly supports the variant management, whereby the adaptation of processes to, for example, different variants of a vehicle model is simplified significantly.

The OTX standard consists of three parts:

  • ISO 13209-1 describes the motivation and cases of application.
  • ISO 13209-2 defines the core language, which includes all language elements incl. procedure declarations, control structures, expansion options and troubleshooting. The core language is kept generic and therefore also suitable for applications outside of the automotive industry.
  • ISO 13209-3 determines the standardized extensions (OTX interface definitions). These provide new instructions and data types, which are, for example, tailored for diagnostic communication with the control units of vehicles, for handling of measured values or for interaction with the user.

Further Standards