There is not one. The is an ECU fuse.
The lower right hand fuse closest to the transmission tunnel is the fuse, if there is 1 in there already! then you are probly getting codes flashing all the time with engine running or not. IF code 12 ONLY with engine OFF just remove the fuse.
The owners manual shows ( fuse # 110 - 20 amp cartridge fuse - for diagnostic connector power and cigar lighter )
The OBD2 diagnostic port doesn't have a fuse and isn't powered by its own circuit.
The fuse is located in the plugin terminal
the OBDII terminal is located on the driver side in the fuseblock panel. There is another diagnostic terminal located on under the the same dash panel just a little further under the dash it is a round terminal looks like something for Toyota to hook their scanner into. Then their is one under the hood about midway back and in the center on top of the engine that is for engine diagnostic . your welcome Jeremy Hadley Arab AL.
its on the positive battery terminal, usually the tab breaks off, so fix this by buying a new terminal end, a waterproof fuse holder for the same style fuse and take the wire plugged into the terminal and cut the plug off and put the fuse holder between that and the terminal. that's how i fixed mine
We have a 2002 2wd TB and I had the same problem i looked it up just like you and all of the online techs were saying look for 15amp (blue fuse) for cigar/power outlet found the fuse finally its in the fuse box under the hood on drivers side your looking for a 20a (yellow micro fuse) its about right in the center of the fuse block look at the fuse block schematic on the in side of the large outside cover its designated CIG on the cover.
The diagnostic port on that car should be next to or in the fuse box panel
the black wire that comes out of the distributor
fuse # 41 - 20 amp mini fuse - cigar lighter , diagnostic connector power
There isn't a jumper terminal, you cycle key on, off, on, off, on and count the blinks.
Fuse # 23 is a 20 amp fuse for the Data Link Connector and cigarette lighter