A system and method for detecting passive intermodulation (PIM) interference in cellular networks are provided that do not require the base station or any sectors of it to be taken offline, that eliminate the need for a technician to make a visit to the cellular site to perform PIM testing, that enable multiple uplink connections to be remotely tested simultaneously, that enable cellular networks to be tested that do not have an accessible connection point to the RF chain, and that enable gradually deteriorating performance due to PIM interference and intermittent PIM interference problems to be detected.