Oil pressure gauge

[crazybiker]

Alrighty, my Oil Pressure gauge came in today, and I plan on installing it as soon as possible.

I originally wanted to use a T-Piece to keep the existing sensor for the idiot light, but thought, it'll be more of a drama.

So I thought, yeah, I'll remove it. Then I heard someone saying that the oil pressure sensor sends data to the ECU to keep the fuel pump going, and that it IS needed, is that true?

But just 5 minutes ago, I unplugged it from the sensor, and started the car, and it didn't stop, nor did the idiot light come on.

So 2 questions;

1. Does the sensor work in a backwards kinda way. When it sees an open circuit or low voltage it shows high-pressure?
2. Would it be fine just to remove the existing sensor and put in my new sensor for the gauge?

[xtreme_sony]

Thats a good question mate, i've never heard of it being needed but i'm not 100% sure so i wont just tell you what you want to hear, i recommend just givin a pro a call and ask about it.

[immortality]

it will run without the factory oil pressure switch plugged in. yes the fuel pump is also switched through the oil pressure switch (you'll note when you turn the engine off the pump runs for a few seconds more....before stopping) the switch doesn't signal the ecu. the ecu has it's own signal for the fuel pump relay (thats what runs the car when you unplug the oil pressure switch and what primes the fuel pump when you first switch on the ignition)

you can run without factory switch but i don't recomend it. if oil pressure suddenly plummets you mignt not notice if your not looking at the gauge, however you are more likely to spot a red warning light popping up on the dash.

[centy]

yeah what he said.
another reason to try to keep the original sensor is that if the fuel pump relay dies then the pump will get power via the oil pressure switch so you can keep driving.

[crazybiker]

it will run without the factory oil pressure switch plugged in. yes the fuel pump is also switched through the oil pressure switch (you'll note when you turn the engine off the pump runs for a few seconds more....before stopping) the switch doesn't signal the ecu. the ecu has it's own signal for the fuel pump relay (thats what runs the car when you unplug the oil pressure switch and what primes the fuel pump when you first switch on the ignition)

you can run without factory switch but i don't recomend it. if oil pressure suddenly plummets you mignt not notice if your not looking at the gauge, however you are more likely to spot a red warning light popping up on the dash.

But when I unplugged the loom from the actual sensor, the car didn't do anything.

No idiot light. No nothing.

[immortality]

But when I unplugged the loom from the actual sensor, the car didn't do anything.

No idiot light. No nothing.

thats correct. the ecu doens't monitor oil pressure. will run as per normal

[crazybiker]

But shouldn't the light atleast indicate it with the Oils idiot light?

Or is it as I said in my original post; An open circuit means it's high pressure?

[immortality]

But shouldn't the light atleast indicate it with the Oils idiot light?

Or is it as I said in my original post; An open circuit means it's high pressure?

no oil light? maybe the globe has blown. does it come on when you switch on the ignition before you start the engine?

[crazybiker]

Yup.

...and after an oil change, it's on for a second or two as the oil runs through.

[axemurderer101]

ive had mine disconnected on my vs for a while now and havnt had any probs, as for people saying its still better to have the factory switch so you still have the engine light i dont see the point cause your gauge is gonna show the oil pressure falling where as with the switch it will only show up when youve lost all oil pressure

[immortality]

Yup.

...and after an oil change, it's on for a second or two as the oil runs through.

strange, gotta have a think about that one

ive had mine disconnected on my vs for a while now and havnt had any probs, as for people saying its still better to have the factory switch so you still have the engine light i dont see the point cause your gauge is gonna show the oil pressure falling where as with the switch it will only show up when youve lost all oil pressure

true...but

if oil pressure suddenly plummets you mignt not notice if your not looking at the gauge, however you are more likely to spot a red warning light popping up on the dash.

which is why i advice that you fit a "T" piece so that you can have both the oil pressure gauge as well as the dash warning light

[axemurderer101]

well considering my gauges are on the A piller i would notice any difference in oil pressure which would show up way earlier than the little red light lol, might be different for people who mount their gauges under the radio

[crazybiker]

strange, gotta have a think about that one

Which is what has lead me to think that an open circuit would mean high-pressure.

Anyone have the voltages of what the sender works at?

I might install it with a T-Piece, I'm not sure.

I know I have to though for certain with my water temp gauge

[centy]

ok here is a possibilty. you have a small short in the wire so check them for continuity.
also try another ecm incase it is a mod someone has done on your car.
also if ever in dought about the pressure gauge then replace the sensor to be safe, it's only about $20

[crazybiker]

It's not the wire. It works after an oil change. I've said that.

It's not the ECU or any mod. First, look above, second, the car is COMPLETELY stock standard.

[SweetWagon]

It's not the wire. It works after an oil change. I've said that.

It's not the ECU or any mod. First, look above, second, the car is COMPLETELY stock standard.

When you disconnect the plug there is no circuit = no light. So are you saying even with the oil pressure switch disconnected your warning lamp still lights up for a second after an oil change??

[crazybiker]

No. With it connected, after an oil change it will.

I'm saying I disconnected it, and started the car. No light.

[SweetWagon]

No. With it connected, after an oil change it will.

I'm saying I disconnected it, and started the car. No light.

That's correct. The light draws power through the switch from fuse 21. (Fuel pump relay) When you disconnect the plug there is no longer a circuit..

[crazybiker]

But theoretically, you'd think if it was an open circuit, the ECU would engage the warning lamp.

[SweetWagon]

But theoretically, you'd think if it was an open circuit, the ECU would engage the warning lamp.

On the VN the oil pressure switch works on its own circuit. It has no interaction with the ECU as far as I'm aware.