Impreza 2.5 RS Sedan AWD F4-2.5L SOHC (2002)
Oil Pressure Sender: Description and Operation
Oil Pressure Switch
The oil pressure switch is located in the front upper portion of the right cylinder block bank. The purpose of this switch is to monitor the operation of
the oil pump as well as the lubricating oil pressure when the engine is running.
1. When oil pressure does not build up (immediately after ignition switch is turned ON):
The diaphragm is pushed toward the cylinder block by the spring force (a force equivalent to the specified oil pressure). This closes the contact
points, causing the oil pressure warning light in the combination meter to illuminate.
2. When oil pressure reaches the specified value (after engine starts):
After reaching the specified value of 14.7 kPa (0.15 kgf/cm2, 2.1 psi), the oil pressure pushes the diaphragm overcoming the spring force. This
opens the contact points and the oil pressure warning light goes out.
