The low temperature transport properties of the pi-d system (DIETSe)(2)MCl4 [ M Fe, Ga] are investigated under the high magnetic fields and high pressures. Anomalous behaviors in the magnetic field dependence of resistance are observed in the magnetic Fe salt below about 2K, while such anomalous behaviors are absent in the nonmagnetic Ga salt, suggesting the strong interaction between the itinerant pi-electrons and the localized moments of d-electrons in (DIETSe)(2)FeCl4.