Electron mobilities and electron-ion recombination coefficients have been determined at 253 K and 170 K by analysing transient electric current through a liquid tetramethylsilane sample. In a conductivity cell ionization was induced by X-ray pulse irradiation under a dc external electric field lower than 10.5 kV/cm. Also results on free-ion yield and electron mobility are discussed. Their dependence on temperature and electric field are investigated.