Wasn't low oil pressure after all Yukon XL Denali 6.2

[briand069]

I thought I'd share this recent repair in hopes it helps someone down the road. A Little background- Friend of mind called to ask what to do, he had no oil pressure showing on the dash gauge but no noise from engine and oil light was off and no warning on DIC to shutdown engine. My first thought was oil pump but the lack of warning light/DIC message was puzzling. Anyways, he took a chance and drove the vehicle home with no issues. After many searches it seemed it must be the sensor since the vehicle was still running but why no light or message? Anyways, he drops by and I hook up my Bluetooth adapter and scan with Torque-BHP and the oil pressure is at 130 psi and not moving. Also had a DTC P0523 Engine Oil Pressure (EOP) Sensor Circuit High Voltage. I cleared the codes and restarted and the dash gauge went up to 80+ and then went back to zero. So, at this point we figured we'd try a new sensor and if that didn't work we'd go from there. Well, today I replaced the sensor and all is well. Pressure is back in range on the dash gauge and the scanner. I was able to replace it without removing the intake manifold and was even able to torque it to spec. What I don't understand is why MIL never came on. Hopefully this will help someone troubleshooting in the future. And I did get the proper socket to remove the sensor which I'm sure made it possible to do without removing the intake.

Brian

 

[tsuintx]

Very common occurence with GMT800 trucks/SUVs, so not a big surprise that would be the case also with GMT900s.

Changed the sensor at some point in pretty much all GMT800s I've ever owned.

 

[Chev454ss]

Same issue?

I have an 09 Yukon XL\SLT with a 5.3L and I have a 0 reading on my gauge and service engine soon indicator on. Oil level good, under 1k miles since oil change (@ GM dealership, asked for delco filter) I have no engine noise nothing telling me to shut the engine down. I'm suspecting the oil pressure gauge switch and screen trick and I have a question. I've seen that a 1 1/16 socket with a 6" extension can be used and 1/2 hour or so to do it. I looked under the hood and I can't see much. Does one have to remove the vortec cover to get to the switch? If so, anything else I need to do/watch for?

 

[tsuintx]

Yes, you need to remove the engine beauty cover so you'll have room to work. It's at the very back of the engine behind the intake manifold, so most of the work is done pretty much blind.

Before you start, take a flashlight and maybe even a mirror and check what it looks like over there. Helps a lot when you are working based off of what you feel. Pretty easy, really.

Haven't done this to a GMT900, but to many GMT800s.

 

[Chev454ss]

Error code check

I stopped tonight and got my code checked, it said high voltage something, bottom line I asked if it meant that my oil pressure sensor was toast, he said yup. So I have the new switch and I'll be putting it in and looking for that pesky screen! Thanks for the suggestions!