Transmission problem
1992 Toyota Previa 4 cyl Four Wheel Drive Automatic 200000 miles

i recently did engine overhaul for my toyota estima emina. it had been lying idle for nearly a year.im put it in drive its moving, reverse is ok, but it seems not shifting gears im suspecting its driving in 1-2 only.did complete transmission overhaul, they told its ok. i put on the Diag machine and its reading DTC error code 42( vehicle speed sensor signal abnormal). the mechanic howver can not locate the VSS, not sure where its located on the vehicle. i have tried many sites but cant get information.do you have any idea of the location of the VSS and generally answers to my transmission problems. Thanx