2003 Suburban Oil Pressure Gauge Stopped Working

[mw442]

I have had a few weird issues with my gas gauge not working it would read below zero, and only if you filled it all the way up would it start working again. I noticed that my oil pressure gauge is now on 0, my wife drives the car so I have no idea how long its been like that. There is no noise, and since the car runs and no oil pressure low or warning chimes I assume that the low pressure switch is working and I have oil pressure or else the car wouldn't run.

 

I am going to try and get out there today if it warms up and would like to test the inside gauge to see if its the stepper motor in the dash or the sender. Does anyone have the pinouts of the oil pressure sensor? From what I have see in other forums if you disconnect the connector, it should read zero, if you short the gauge it should read 80. Just didnt know what pins to short. There are 3 pins. I assume one is ground, one is for the low oil pressure switch, the other goes to the sensor. I am going to try and get a mech gauge on there as well dont know if I can get back there from what others have said its pretty hard to get to.

 

Thanks!!

[mw442]

Ok its like 20 degrees out. Pulled the plastic cover and tried to get my hand down there and there is no way I can get my hand down there. I have the 8.1 liter and I am assuming its in the same place as the 6.0 liter engines.

[redvett]

THe gauges on the GMT800 are class 2 serial data so i doubt its the sender as you would have an SES light. I am betting on the cluster.

http://content.chiltonsonline.com/content/...D_GM_013972.pdf

[snake428]

If a sender drops on these it will not allways set a light so don't count on that alone

[mwitte]

Ok so I pulled my scanner out and I have a P0523 engine oil pressure signal high. Looks like the sensor....

Apparently I was looking at a incorrect cluster diagram, I thought that the vehicle had a analog signal from the pressure sensor and that it also had a low oil pressure switch. So I would have thought that if it doesnt see oil pressure it would ignite the Low oil pressure light on the DIS and that the car wouldnt run if it saw a no oil pressure signal.

 

Guess I will have to try and replace that stupid sensor its so damn hard to get to.

Crap!!

[mwitte]

So if I clear the P0523 code, and start the truck, the oil pressure gauge goes to 80. After a minute or so it drops to 0 and sets the code again. I back probed the sensor pin at the PCM and got no connectivty to ground, and it read 5V when started/not started. So that tells me either the ground to the sensor is bad or the sensor is open to ground. Since it just went I really doubt its the wiring.

 

Guess i am doing the sensor cant wait...