696BMX

dire need of all kinds of help. newbie here. here is what i got going on. 1990 4wd 4runner 3.0 auto trans. i picked up a 97 2wd tacoma 2rz truck manual trans. ill start with this question. unplugging the ecu on the tacoma there was three plugs going to ecu. two of which came through firewall and one look like it was routed toward the driver side behind dash. do i need this plug and what it goes to for my swap?