Oil Pressure Switch On-Vehicle Inspection
WARNING: This page is about a different car, the 2004 Suzuki Vitara. However, it is still accessible from the selected car via links, so may be relevant.
Use an ohmmeter to check switch continuity.
Oil pressure switch specification
During Engine Running: No continuity (INFINITY ohm)
At Engine Stop: Continuity (0 ohm)
Courtesy of SUZUKI OF AMERICA CORP.