Hombre XS Space Cab 4WD V6-4.3L (1999)
Pressure Regulating Solenoid: Description and Operation
Transmission Pressure Control Solenoid
Important: Transmission pressure control solenoid resistance should measure 3- 5 ohms when measured at 20 °C (68 °F).
The transmission pressure control solenoid is an electronic pressure regulator that controls pressure based on the current flow through its coil winding.
The magnetic field produced by the coil moves the solenoid's internal valve which varies pressure to the pressure regulator valve.
The PCM controls the pressure control solenoid by commanding current between 0.1 and 1.1 amps. This changes the duty cycle of the solenoid, which
can range between 5 percent and 95 percent (typically less than 60 percent). 1.1 amps corresponds to minimum line pressure, and 0.1 amps
corresponds to maximum line pressure (if the solenoid loses power, the transmission defaults to maximum line pressure).
The PCM commands the line pressure values, using inputs such as the throttle position sensor.
The pressure control solenoid takes the place of the throttle valve or the vacuum modulator that was used on the past model transmissions.
If the duty cycle drops below 5 percent or rises above 95 percent, DTC P0748 will set.
