2nd Gen Prius OBD2 Port Not Communicating

First step to is to confirm its not the code reader you're using... Most code readers are counterfeit junk that don't work... I had to buy and return 3 of them before I got one that worked! Here's buyers guide: Hybrid battery diagnostic and repair tool for Toyota and Lexus

 

Could be a problem with your adapter, could be a problem with the female terminals in the OBD connector (you would need a single male terminal of the correct size to check fit when pushed in- there should be slight but noticeable drag when pulling).

Does that OBD adapter work on another car?

Posted via the PriusChat mobile app.

 

I've noticed similar problems in my gen too and those code readers I tend not to use sometimes if I unplug them and reinsert them they seem like they work but I don't know how deep they go I have text stream on a cf-19 with a dongle that seems to work it's red and it lights up green and red is data moves I don't know how to buy another one to get an extra as the j standard for these things seems to be all over the place the replacement or the piece that I got with the Toyota tech stream computer I bought from the dealer I believe this is a replacement cable but it works

 

The wiring diagram shows a 7.5A OBD fuse (in the driver's side interior fuse block?) specifically for the OBD2 connector. Have you checked that fuse with an ohmmeter?

 

Did you figure this out?

 

Did anyone figure this out? I'm having the same problem. I need to get my car smogged, I went to two different places and neither one could "communicate" with the odb2. My cheap personal scanner worked perfectly and i scanned the car and no codes, but the tech told me there's no power on port 16 in ODB2 plug. i put my electrical reader in there and it said 11.4 volts. Does anyone have any idea what else this could be. I checked all the ECU fuses and the ODB fuse and no problem there. the cigarette lighter still works so I don't know what to do

 

That 11.4 volts is very problematic that needs to be 12.3 to 12.7 to keep up the electrical system in the car and all the computers communicating so you're 12 V is questionable at best

 

This is almost urban legend status. I haven't found it to be so. At this level, it is certainly necessary to charge it up before doing further diagnostics. The computers will not complain until the voltage is much lower or you get frequent voltage drops into the less than 10.5 – 8.5 volt territory because the battery has lost all capacity.