Possible communication errors

[DENTSLAYER]

The oil pressure light on my 07 Avalanche LT went on a couple weeks ago. I pulled over, shut off the engine, let it rest, checked the oil (it was good), and started it back up. The gauge was working again. That tells me my oil pressure is fine and the sensor needs to be replaced. Ok cool.

I bought a new sensor but put off replacing it because I've been very busy and didn't deem it prudent. I find the gauge works sporadically. Last weekend I drove down to another city and had no issues whatsoever until I slowed down to get off the highway. Thats when the oil pressure light comes on. Over the weekend it would come on randomly. I'd punch the gas and the gauge would work again.

It gets weirder. On the way back, there was an accident on the highway near my city. I was crawling for 20 minutes before I could pass the mess. When I finally did pass it, I noticed my dash reads "engine reduced power". I've got the pedal all the way down, doing 4000 rpm, and can't get above 93kph. I presume this is limp mode. I pull over, shut her off, start her back up, and I'm back to full power.

Now the oil pressure light has developed a pattern. It works when I'm idling, and it works when I'm going over 70kph. Anywhere in between and the gauge is at zero and lunching the gas no longer corrects the issue.

Then it did another new weird thing. The other night I made it 2 blocks away from work and the engine shut off while driving without warning. I struggled to get it started again, and when it did, it shut off again after driving 2ft. This happened several times before I was able to drive it very slowly back to the shop where I let it sit for a few days.

I took it to get gas last night. Oil pressure light is still doing its weird thing. Check engine light is on. Motor is running and I'm at full power. But I don't trust taking her across the city, let alone out of town.

A friend suggested it may be wiring beginning to short out. I attempted wiggling wiring harnesses under the hood while the vehicle was running hoping it would shut off my truck, indicating where the issue is. Nothing happened.

Im at a loss for words at this point. There's no warranty on this truck and I have no idea what do to next. I'm expected to so some work 5 hrs away in 2 weeks and would like to have this issue resolved by then, if not sooner. Please help!

 

[MS03 2500]

There's not much you can do at this point, except to replace the sensor. Don't forget to replace the screen/filter under it

 

[DENTSLAYER]

There's not much you can do at this point, except to replace the sensor. Don't forget to replace the screen/filter under it

I had thought the "engine reduced power" and the engine truning off while driving would indicate something else is wrong with it. I suppose I may as well follow your advice, hope for the best, then go from there. Thank you!

 

[ygmn]

Any Check engine light codes?

 

[DENTSLAYER]

Any Check engine light codes?

My scanner isn't working properly right now but according to my last scan, there were issues with the throttle position sensor as well as the oil pressure sensor.

I replaced the oil pressure sensor today. The oil pressure gauge is no longer acting up. However, while on my test drive, the motor shut off again. Service stabilitrak and traction control lights have appeared on the dash. I had to drive it in reverse to get it back to my shop

I feel like my next step should be to replace the throttle position sensor. If the problem persists, I'm told it may be my ECU. What are your thoughts?

 

[DENTSLAYER]

There's not much you can do at this point, except to replace the sensor. Don't forget to replace the screen/filter under it

I replaced the oil pressure sensor today. The gauge is no longer misbehaving. However, the motor continues to shut of while driving.

Service stabilitrak and traction control lights are on the dash. And according to my most recent scan, there's an issue with the throttle position sensor.

Strangely, I can drive it in reverse without issues, as thats the only way I was able to get it back to my shop after driving a few blocks before the engine shut off today.

Im so lost at this point

 

[MS03 2500]

I replaced the oil pressure sensor today. The gauge is no longer misbehaving. However, the motor continues to shut of while driving.

Service stabilitrak and traction control lights are on the dash. And according to my most recent scan, there's an issue with the throttle position sensor.

Strangely, I can drive it in reverse without issues, as thats the only way I was able to get it back to my shop after driving a few blocks before the engine shut off today.

Im so lost at this point

If you have a code reader, first clear all the old codes then drive it again then re-read the codes.

 

[ygmn]

Without codes you are guessing and wasting money on parts.

 

[Rothy]

Check 4ws and auto4x4 fuse under hood but it sound like issue with your regulated voltage control system. That would explain why it allows you to drive and stays running in reverse gear; it’s probably a safety feature when in reverse or 1. And it would cause truck to shut off intermittently because it is not restarting the alternator and charging system like it’s supposed to when in drive. This won’t cause the light to come on because as far as the system is concerned you don’t have a charging issue