oil pressure sensor questions
The three wire sensor talks to the PCM.
There is no oil pressure signal that I've found from the PCM that leaves the PCM.
From what I can read in the schematics, there was no gage in the GTO, just an oil pressure light.
Will the PCM shut the engine off if there is no oil pressure?
I would like to get at least a working oil pressure light, if not a gage.
Does the signal for the oil pressure light come from the UART or some other serial data port? Is there any way to trigger a light off of that?
Can I tap into the output from the sensor and run an electric aftermarket gage? How would I scale it properly?
If I put in an aftermarket gage, do I just put a tee in where the OEM sensor is and leave the OEM sensor there to feed the PCM?
I have the engine running, sounds fine, but before I run it for any length of time I'd like to know that I don't have a problem with the pickup tube or something....
The three wire sensor talks to the PCM.
There is no oil pressure signal that I've found from the PCM that leaves the PCM.
From what I can read in the schematics, there was no gage in the GTO, just an oil pressure light.
Will the PCM shut the engine off if there is no oil pressure?
I would like to get at least a working oil pressure light, if not a gage.
Does the signal for the oil pressure light come from the UART or some other serial data port? Is there any way to trigger a light off of that?
Can I tap into the output from the sensor and run an electric aftermarket gage? How would I scale it properly?
If I put in an aftermarket gage, do I just put a tee in where the OEM sensor is and leave the OEM sensor there to feed the PCM?
I have the engine running, sounds fine, but before I run it for any length of time I'd like to know that I don't have a problem with the pickup tube or something....
I bought a t-fitting/ metric to NPT from S & P and installed the factory oil sender and dakota digital sender on it behind the intake on the oil pressure sender......
I would not run it unitl you have an actual gauge on there, and thats just me...
Bozz
Last edited by bozzhawg; Feb 16, 2011 at 10:01 AM.
However, If your oil pressure sender is one of the larger "diaphragm" types (about 1.5"-2" wide) then it will not fit comfortably in the stock location behind the intake manifold. It will interfere with the back of the intake manifold and the vacuum lines. So here's what I did...
Instead of putting the large oil pressure gauge sending unit up behind the factory manifold, I put in an oil pressure switch for an "idiot light." on the dash. The switch is GM part number 14014599 and was about $6. If there is no oil pressure (less than about 2 pounds) it will close the circuit and light up the idiot light on the dash. As soon as it detects oil pressure (I think over 8 lbs) it will open the circuit, and the light will turn off. If oil pressure goes down to about 2 pounds, the light will turn back on. You get the idea!
I also wanted an oil pressure gauge, so I got my oil pressure gauge sending unit and installed it on the oil block-off plate down by the oil filter. I got an oil block-off plate from a Corvette, which was already tapped with a 12mm hole for the oil temp sender. The tapped hole was angled so that the pressure sender fit great with plenty of clearance under the exhaust manifolds.
I had to buy an adapter for each sensor. The hole on the top of the block was 16x1.5mm, and the oil pressure switch was 1/4 NPT, so I needed a 16x1.5 male to 1/4 NPT female. The hole on the oil block-off plate was 12x1.5mm, and you will need an adapter to match your oil pressure sending unit.
If you are going to buy an aftermarket oil pressure gauge, many of them come with the appropriate sending unit. If you already have a gauge in your car, get your hands on the sending unit the car used from the factory, and use that one with an adapter.
I believe the "serial data port" is just the diagnostic port - the place you would plug a scanner so you can troubleshoot a check engine light, etc.
The three wire sensor talks to the PCM.
There is no oil pressure signal that I've found from the PCM that leaves the PCM.
From what I can read in the schematics, there was no gage in the GTO, just an oil pressure light.
Will the PCM shut the engine off if there is no oil pressure?
I would like to get at least a working oil pressure light, if not a gage.
Does the signal for the oil pressure light come from the UART or some other serial data port? Is there any way to trigger a light off of that?
Can I tap into the output from the sensor and run an electric aftermarket gage? How would I scale it properly?
If I put in an aftermarket gage, do I just put a tee in where the OEM sensor is and leave the OEM sensor there to feed the PCM?
I have the engine running, sounds fine, but before I run it for any length of time I'd like to know that I don't have a problem with the pickup tube or something....
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I also ran the aftermarket sender off of the bypass plate above the oil filter. Just drilled and tapped again..
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I could be wrong but dosent, the BCM actually get its engine data from the PIM that inturprets the information from the PCM/ECM?
I am pretty sure the engine info goes to the PCM/ECM, then the PIM inturprets the data serial so that the BCM can read the information.. The PCM/ECM and BCM do not speak the same language....
Bozz
I don't have room by the oil filter because I have my manifolds machined to tuck in right along the block. I might get it in there, but I'd never be able to get to it again.
I was thinking more along the line that the stock sensor sends out a variable voltage, examble, .5VDC = 0 psi, 3.5VDC = 80 psi or something.
Since the PCM doesn't use the signal, and I have plenty of room by the firewall, I guess I'll hook up both an aftermarket gage and also tie into the OEM oil light on the Volvo.
Many thanks!
Here is a manner in which you can run two gauges from one sender.
http://a.moirier.free.fr/Instruments/Instruments-g%E9n%E9ralit%E9s/Dual%20instrumentation.pdf
I will be trying this out for the temp & oil signals for my 92 k1500 LQ4 swap with a '96 dash.
I know the PCM doesn't do anything with the info for the oil pressure, but is it still receiving a value or is the sensor purely a dummy sensor that only measures low/high oil pressure?
I want to run a scan gauge or ultra gauge, which reads info from the PCM through the OBD2 reader port, which is why I am asking.







