Hey all, anybody knows what is the exact purpose of oil pressure switch? Well okay, you'd say, to monitor oil pressure, now read on. This is 97 maxima. I pulled the connector off the switch, started engine and guess what! no changes, no CEL, no "oil light", engine runs as usual like nothing happened. So queston is - why is it there if disconnecting has no effect at all?

Full story: have intermittent stalling on highway speeds and in town driving as well. I have oil leak, supposedly coming from upper/lower oil pan and running all the way to oil pressure switch (those who had those leaks know how leak follows that cable all the way down to switch connector). Heard somewhere that low oil pressure shuts off fuel pump (not sure if this is true though for 4th gen maximas). Decided to disconnect oil pressure switch to simulate condition when leaking oil causes bad contact at the connector, to verify that fuel pump cuts off because of that bad contact, following me so far? Please, share, thanks a bunch!

 

Oil pressure switch drives the low oil light.

If it does any more, it should be easy enough to find on the wiring diagram.

 

All the oil pressure switch does is ground one side of the light when there is little oil pressure (below 1-3 psi). This turns the light on. It has no effect on any other system in the car.

 

So all oil pressure switch does is triggers oil light (well when pressure is low of course) and has no effect on ECM- good to know, thanks folks. Read somewhere that on many GM cars for example, oil switch sends a signal to ECM and shuts off fuel pump, if pressure drops thus protecting the engine from further damage. Apparently this does not relate to 4th gen maximas then.
Long story short, stalling has nothing to do with oil pressure, even if it is low, no such safety feature, thanks again for clarifying.

Well anyone can sum up common causes for stalling please (both hwy and city driving). Exclude MAF- has been replaced lately.

 

I would check the ECTS. Also, if you have rough idling, clean out TB, IACV. Do you have any codes?

 

Lots of cars have a oil pressure fuel pump interlock.

 

ECTS has been replaced lately, and it shows correct ohms under certain temps as per FSM specs, so the problem is elsewhere. No, no codes. Interesting thing is that on highway it did not require a restart, engine would just stall for about 3 seconds, car would just coast still being on Drive, and then picked up again- bad ignition switch maybe? Unfortunately, I did not pay attention to instrument panel during the stall. Rule of thumb is if no lights on dashboard during stall=ignition switch is gone, anyone had this before?

 

Its only there for the oil light it wont effect the car at all ......Mine broke off so i couldnt plug it up and it did nothing to the car just the oil light didnt come on when the oilwas low or bad

 

Yeah that has happened to me before and I didn't have any codes. But like you said, after a few mins, it started right back up as if nothing happened. Definitely replace your ignition switch..

 

Common causes I’ve seen:

Dirty TB or IACV
MAF

That’s it. I’ve heard of coils being the culprit at times but that hasn’t been my issue. Mine was the MAF

I don’t think your Oil Pressure Switch is the problem.