Do ODB-II/EODB/JODB readers for dealers/mechanics show more than consumer readers?

Question

When you go to an auto parts store and buy an ODB-II/EODB/JODB code reader, you will be buying a device that will read vehicle fault codes via a standardized data port.

Do vehicle manufacturers sell code readers to dealers/mechanics that read more data than is visible on the consumer readers?

If so, does clearing codes using a consumer reader (yes, technically not a reader at that point) also remove any data that only the dealer/mechanic can see with their devices?

Inspired by reading this question : Should I clear Prius odb2 codes?

Answer 1

Yes

Manufacturer-specific diagnostics tools can often read additional information that goes above and beyond the standardised OBD-II codes, particularly on modern cars with additional electronic control units for various ancillary functions.

While manufacturers don't generally make their tools generally available for purchase tools with these capabilities aren't always dealer- or mechanic-only. Third-party tools like OBDeleven, Ross Tech's VCDS and Carista are readily available to consumers too.

If so, does clearing codes using a consumer reader (yes, technically not a reader at that point) also remove any data that only the dealer/mechanic can see with their devices?

Sort of - there's always (potentially) proprietary data/logging recorded that may not be cleared by consumer kit, even those with additional capabilities such as described above. A generic OBD-II device isn't going to clear codes in the ECMs it can't interface with but ones with extended functionalities can generally clear codes in those systems they interact with.