Linear Pressure Solenoid SL1, SL2, SL3, SL4 And SL5
The linear pressure solenoids, SL1, SL2, SL3, SL4 and SL5 are located in the transmission control system, which is mounted on the front edge of the transmission. The linear pressure solenoids consist of an electrical coil which controls a hydraulic valve. The solenoids are controlled by a pulsed (PWM) voltage and grounded via the Transmission Control Module (TCM). The hydraulic function of the solenoids is linear. The hydraulic valves are controlled by the varying current resulting from the current pulse ratio. With a high pulse ratio, i.e. high current strength (approx. 1 A), the system pressure is low, and with a low pulse ratio, i.e. low current strength, the system pressure is high. In the event of an open circuit the system pressure is at a maximum which results in hard gearshifts. Here the hydraulic valve is fully open.
The solenoids can be diagnosed.