I'm getting the low oil pressure warning display. I've tried resetting using my OBD II reader.
The mechanic replace the oil pressure switch also.
The oil level is good.
Anyone else run into this problem?

 

What about the ECU you just got repaired from SIA?
What's changed between the last known good (oil pressure-wise) configuration and the new ECU?

 

Don't drive the car with the low oil pressure light on you really have no idea how low the pressure is or if there is no pressure, engine damage is just around the corner if it hasn't already happened.

Your mechanic sounds like a glorified parts changer. They should have used a mechanical oil pressure gauge to read what the actual pressure is rather than guess that the sensor is bad. Willyumd is on to something the oil pressure and oil level switch both run through the engine ECU to get to the instrument cluster.

I attached a pdf of the service manual that goes over checking oil pressure, you don't have to wait for the engine to warm up you'll know immediately when the engine starts if you have pressure or not.

 

What jharris400 said, use a mechanical gauge to verify pressure.

 

Was the replacement switch OEM or aftermarket? If aftermarket, you could have gotten a new switch that was junk (Dorman).

 

I've had that light come on and the problem was no oil pressure. You should hook a mechanical gauge (Harbor Freight has a cheap one)to where the pressure switch is on the oil filter adapter. The factory switch comes on at 4 psi which can destroy a tight tolerance engine very quickly. My issue ended up being a clogged oil pickup screen. My pressure was normal at idle but at higher rpms it would quickly drop to zero.

https://www.clublexus.com/forums/ls-...e-freeway.html

 

As mentioned throw a mechanical gauge on it and check for sure what it is

 

+1 for this. Don't want to chance a low oil pressure event.

 

I'm going to replace the oil pressure switch with an AC Delco.
Supposedly the mechanic replaced it already.

 

Prob not the time or place to continue playing with aftermarket parts.
The OE part is not that expensive- https://parts.righttoyota.com/oem-pa...nit-835300e010

 

That doesn't show it fits a Lexus.

 

Look at the part numbers it replaces.

 

https://www.lexussouthatlantaparts.c...35300E010.html

I originally referenced a Toyota parts retailer to show you can find it easily at any Toyota dealer.

 

My light bulb burned out maybe I should replace the light switch.....

 

I couldn't cancel my Amazon order for the AC delco oil pressure switch so I'm going with that one.