DTC P0843 (6-Speed A/T) (2017 2018 2019): General Description
Transmission fluid pressure switch A (2nd clutch) is installed in the hydraulic pressure circuit to the 2nd clutch. When hydraulic pressure is supplied to the 2nd clutch, the switch is turned on. When hydraulic pressure is not supplied to the 2nd clutch, the switch is turned off. The signal from transmission fluid pressure switch A (2nd clutch) is input to the powertrain control module (PCM). The PCM detects the hydraulic pressure supply conditions at the gear change to 2nd gear (1st -> 2nd) to reduce the shock that occurs at the gear change. If transmission fluid pressure switch A (2nd clutch) is off while driving the vehicle with the rotation speed ratio of the input/output pulses is that of the 2nd gear ratio, the PCM detects a transmission fluid pressure switch A (2nd clutch) failure and stores a DTC.