Circuit Description
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The Pressure Control (PC) solenoid valve is a PCM controlled device that regulates the transmission line pressure. The PCM compares TP sensor voltage, engine RPM, and other inputs to determine the appropriate line pressure for a given load. The PCM regulates line pressure by applying a varying duty cycle to the PC solenoid valve based on the resistance of the solenoid, and the amperage needed to obtain optimum line pressure. The applied amperage varies from 0.1 amps for maximum line pressure to 1.1 amps for minimum line pressure.
If the PCM detects a PC duty cycle that exceeds 95 percent or less than 1.9 percent, then DTC P0748 sets. DTC P0748 is a type "C" DTC.