Hello and thanks for any help in advance, I own a 2008 Suburban with the 5.3. Vehicle has 296,xxx miles and has been extremely dependable up until about the past few weeks. When I purchased the vehicle it had some dash lights and messages running across the cluster that didn't effect performance so they kinda went ignored as this is a work vehicle for me. Stabiltrac, abs light, park assist were always on however the issues have turned into the fuel gauge has stopped working altogether and then a day or so later while driving i noticed the oil pressure gauge dropped to 0 a message popped up no oil pressure and to shut down the engine so I did so. Checked the oil and it was ok, no lifter noise or knock so I proceeded on my 4 hour trip with no further issues or than the gauge going from 60 lbs to 0 lbs every so often with the notification. Further into the trip I got a "Reduced Engine Power" notification, I eased into a parking lot and removed the positive battery cable in a desperate attempt to reset the computer, this did work as that particular issue hasn't come back around. After loading my daughters furniture onto my trailer I started the vehicle and it stalled once I put into gear. I started it and drove about a 1/4 mile and it died again. Long story short it was towed back north 4 hours to my home via a uhaul box truck . Vehicle has been parked for a few days now, i did undo both battery cables and tied the together, drove it around the block and it does stay running now but I fear if driven further it'll leave me stranded. Where do I start? Should I replace the ECM? Check grounds? could that be a issue? I'm mechanically savy but this electrical stuff gets me most of the time. I did scan it and 3 codes came up... evap, knock sensor and cam sensor. I just don't see these sensors along with the fuel sensor all going bad at once.... Any help would be greatly appreciated as this is my only vehicle, Im new to this area and have a few crotch goblins to cart around.

 

I understand that I'm new here but nonetheless I'd like to think if 600 people had seen this thread, someone surely could offer me some advice on where to start

 

Hey Shawn, it's not a new thing, just noone has any ideas for you so far, sorry. Stupid computers are out of my league but similar posts seem to often get resolved with new batteries, check your alternator, and clean (not just check) all your grounds - a very tedious process.
Have you had it scanned for any codes that might help you?

 

Well - this is the first time I've seen the thread, as I tend to lurk in the GMT400 and GMT800 pickup truck threads...

I would START by not resetting things, and hooking an ODB2 reader to it after a test drive, to see what is going on. If you don't have one, it's a good tool to have in your garage these days, especially if you keep vehicles for 300k miles.

That oil pressure gauge jumping up and down like you saw sounds like a failing oil pressure sender. It's a fairly easy thing to replace, if you can reach it. On my 2006 Vortec, it's at the back of the engine, and you need a socket, extension and U-joint to reach it without removing the intake manifold.

That said, that is an engine with a lot of miles on it, so there could be lots of other things going on as well. I am just addressing the low hanging fruit here...

 

Thank you for the insight, I'll start with that I suppose. Under $20 and may at least stop the cutting out. My first thoughts were the ECU as it seemed as though everything started acting up all at once. Once again thanks for your time

 

Yeah - the oil pressure sender cutting in and out could be the cause for the ECM to put you into limp mode, if it thinks the oil pressure is too low. Definitely start with that.

Note that there is a screen in the hole where it in installs. Be sure to replace that too as it could be clogged. The oil pressure switch/sender I bought from Rockauto.com included that screen. I also ordered a special socket for it as well.

This HOWTO on the website includes an embedded video showing how to change the oil pressure sensor on your generation truck. For this exercise, doesn't matter if its a Silverado or Suburban...

Chevrolet Silverado 2007-2013: Why is My Oil Pressure Low? | Chevroletforum