K 1500 Truck 4WD V6-262 4.3L (1991)
Transmission Position Switch/Sensor: Description and Operation
Pressure Switch Manifold (PSM)
Pressure Switch Manifold
The Pressure Switch Manifold is a gear range sensing device used by the PCM to sense what gear has been selected by the vehicle operator. The PSM is
located on the valve body and consists of five pressure switches combined into one unit.