Circuit/System Description

WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Fluid Pressure Switch 3 also known as the Oil Pressure Switch is part of the A90 Logic/ROM module which is part of the control solenoid valve assembly which has no serviceable parts.

The Transmission Fluid Pressure Switch 3 shares the Transmission Manual/Automatic Date Output circuit with the ROM Assembly in the transmission. The ROM Assembly uses the Transmission Manual/Automatic Date Output circuit as a low speed serial data circuit between the ROM Assembly in the transmission and the transmission control module. The ROM Assembly only communicates with the transmission control module when the RUN/CRANK circuit goes high. Data is transmitted once during the drive cycle and happens quickly. After that data exchange, the function of the Transmission Manual/Automatic Date Output circuit becomes the Transmission Fluid Pressure Switch 3. The Transmission Fluid Pressure Switch 3 reflects the status of the high clutch oil pressure. The Transmission Fluid Pressure Switch 3 is normally open. When the clutch is commanded ON the Transmission Fluid Pressure Switch 3 closes. The DTC sets if there is a mismatch between the TCM commanded high clutch position and the status of the switch.