Problems in Nissan Maxima V6 3.0 1994

Hello, I would like to know if someone can guide me in the problem of a Nissan V6 3.0 1994, the full engine was repaired, but it is with a problem, ABC, cruise speed and automatic box, which can be, it can be the sensor? They tell me that the three things work with only one ... or sulfatado a cable ... the cueion that I do not know where the blessed sensor is