Low oil light - wire in a/m sensor?

Hello.

It is well established that the low oil light on the 1GR and 2TR equipped Tacomas is mostly useless.

I'm considering installing an a/m oil pressure sensor and wiring it up to a buzzer, but I don't know the normal operating pressures of the 1GR-FE. I understand they are a relatively low oil pressure engine, but does anyone have data?

Thanks.

edit:

Oil pressure : at idle 29 kPa (0.3 kgf/cm2, 4.2 psi) or more
Oil pressure : at 3,000 rpm 294 to 588 kPa (3.0 to 6.0 kgf/cm2, 4.3 to 85 psi) or more

https://www.jdmfsm.info/Auto/Japan/Toyota/Hilux Surf/Hilux Service Manual/repair2/html/frame_rm0000019tu000x.html

 

Hold on let me fix that, The oil light on ALL Toyotas are useless!

 

Given how low the idle is, I do not think a direct pressure tied AV warning is going to make me very happy. The only thing I can think to do is add a lot of trouble and complexity by having a cutoff for the alert below a certain RPM. The idea being, if I'm above some value, let's say 1k RPM, the AV is armed for some pressure, 25 PSI.

The net effect being, I lose the alarm at idle, but if I hole an oil pan or blow a seal, finding out about it as soon as I touch the throttle is better than nothing and I'm more likely to have gas on when I hit something hard enough to hole the oil pan or blow a seal.

Now that I've justified the logic for the silly project, we have to fuck with implementation.

I really, really don't want to go too digital on this. Here is a question for the Big Brains:

Is there somewhere I can grab a signal for RPM? Does this truck pass that value somewhere even crudely as say a voltage range or something? I am strongly considering building an aux ECU to handle some odd details like "door lock on (D)rive" and other functions, so it would be really convenient if there was an elementary output somewhere I could feed in RPM as well.

 

There is a dedicated Tach line accessible at Pin 9 (Black/White) of the DLC, it's a 0-12v square wave 3 pulses per revolution of the crank.