Inspect Oil Pressure Switch Continuity

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the connector from the switch.
Check that continuity exists between terminal and ground with the engine stopped.

Fig 1: Testing Oil Pressure Switch
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: Oil pressure should be over 24.5kPa (0.25 kgf/cm² , 3.55 psi). If operation is not as specified, replace the switch.

Check that no continuity exists between terminal and ground with the engine running.