AFAIK, strictly a dumb light based on yes/no to a set, expected oil pressure level. Couldn't tell you the finer details re how that works though, there is an acceptable range because pressure will vary by temperature, rpm, etc. Have to look-see if there is info in the shop manual about it.
For a 3.5L NA engine
Oil pressure Minimum 30 psi @ 1,500 rpm with engine at normal operating temperature
For a 2.0EB engine
Oil pressure (hot @ 2,000 rpm) 200 kPa (29.01 psi) - 268 kPa (38.87 psi)
For a 3.5L EB engine
Oil pressure Minimum 30 psi @ 1,500 rpm with engine at normal operating temperature