2003 Volvo XC90 Base, FWDFACTORY OEM SERVICE PROCEDURE

Linear Pressure Solenoid

Fig 1: Identifying SLT Solenoid In Transmission Control System
GLL149397Courtesy of VOLVO CARS CORPORATION

The linear pressure solenoid,, is located in the transmission control system, which is fitted on the front edge of the transmission. The linear pressure solenoid,, consists of an electrical coil that controls a hydraulic valve. The solenoid is controlled with a pulse width modulated (PWM) voltage and is grounded via the transmission control module. The solenoid has a linear hydraulic function. The hydraulic valve is controlled by the varying current resulting from the current pulse ratio. With a high pulse ratio, i. e. high current strength, the system pressure is low. 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, resulting in hard shifting. The hydraulic valve is then fully open.

The solenoid can be diagnosed.

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