DTC U1260: Problem in PCM-to-ATFP Control Unit Communication Circuit: General Description

The auxiliary transmission fluid pump (ATFP) system consists of a 3-phase brush-less motor to drive the ATFP, the ATFP control unit, and the ATFP relay. The PCM and the ATFP control unit are connected with a bi-directional communication line, and the ATFP control unit and the ATFP share information on the 3 phases, U, V and W. When the powertrain control module (PCM) transmits the rotation indication to the ATFP control unit, the ATFP control unit drives the ATFP according to the indication. As for the communication protocol between the PCM and the ATFP, the PCM transmits to ATFP control unit and then the ATFP control unit returns to the PCM. When there is no return for a set time after the transmission from the PCM, a DTC is stored.