Diagnosis terminal-inside engine bay

[Jungoes]

Just a quick question, but what exactly is the diagnosis connection inside the engine bay used for? I'm just curious as i checked through the site to see if i could find some info on it but didn't. Will this be used for information the OBD2 connector cannot supply?

 

[Socco]

The OBDII port inside is more of a read-only access of selected parameters. The one on the engine is for Toyota techs to scan the truck with. Its for access and testing of things like the ABS and SRS.