I don't think that is the fuel pump plug. Where exactly did you find it? On the rear seat strut, maybe? The five wire plug is under the access panel under the rear seat on the top of the fuel tank. I strongly doubt your rig is any different from all the others, unless maybe you have a 2003, not a third gen....
here is a pic of the access plate. The five wire plug is under there.
See the five wire socket on top of the tank?
__________________
'99 4Runner SR5 5spd 3.4L V6 4WD(U.S), original '99 Talls in front, OME 906s in back, Hella fogs, Trekmaster shocks in front, Billy in back, no running boards, FIAMM horns, Alpine sound, Michelin LTX M/S2's, owned since new.
'97 HiLux SW4 5spd 4WD(Japan model bought in Brazil assembled in Argentina, very close to a 3.0 4Runner/Surf)
'71 FordWillys Jeep CJ5 (with straight six Ford Maverick 3.0 liter engine--lives in the mountains north of Sao Paulo Brazil)
My Backyard Frame Swap