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At a loss... NO idea...

socrates

By socrates
in Ask A GM Technician

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socrates Enthusiast

socrates

Posted
Posted

Hello,

I'm lost.

I have a 2002 chevy silverado 1500 4.8 v8 ext-cab. Everything had been running great I just replaced the water pump within the last year as well as the fuel pump (air tek). My truck is at about 115,000 miles and has had regular fluid changes as well as a spark plugs changed. About 2 months ago I was driving to pick up my gear from the service center (about 30 minutes from my fire station) (I'm a firefighter here in socal). and I noticed my rpm's suddenly drop and it seemed like my truck randomly down shifted really low like it was going to die and it lost power but then came back up and then did it again but then came back up. Anyways I pulled in and got my gear. I then drove back home (about 200 miles from the service center). I drove around town all that week and then had to go up north for some training which was 6 weeks long. I drove up north (about 300 miles) without any issues and I drove around town multiple times with no issues then one day about 4 weeks in I was heading for sacramento and about 10 minutes into my trip it started doing the same thing except this time it completely shut off. However before it shut off it would drop rpm's a couple times and then go back to normal and then do it again. Then finally it would unlock the doors and flash a battery light and the whole car would be shut off. I had to pull over and attempt to start it again and it would be fine for a few minutes and then do it again. Long story short tested the fuel pump (it was fine) and tested the alternator no issues. I then found out I had a bad battery I replaced the battery and had no issues I drove home (300 miles) and then back to my station (another 200 miles) no issues but when I tried to drive to my training center today it randomly died in the middle of the freeway again and then started right back up and died in the next intersection. I ended up getting it started and parked it in the parking lot and had a buddy pick me up and then at lunch I drove it to the a shop who looked at my fuel filter and checked everything again no issues however when they were about to give my truck back it died on them and they immediately hooked up their code reader. There were a ton of codes basically stating that the engine died. Some of the notable codes were "ECBM connection loss", crankshaft position sensor and transmission sensor. However these aren't hard codes because they immediately disappeared. I'm at my witt's end I have no idea if I should just trade it in or dump more money in it till someone correctly figures it out. Any ideas or has anyone seen anything like this? My buddy who is a mechanic where I live recommended that I turn my ignition switch to the on position for 10 minutes and then turn it off for 15 seconds and start it he said that that sometimes reprograms the ignition and the new battery to reset the computer. Anyone else have any ideas?

Thanks,

 

PhilB Enthusiast

PhilB

Posted
Posted

Sounds like a wiring issue. Check your cables coming from the battery. Sometimes the cables develop corrosion inside the sheathing so it may not be noticable. This shoulds similar to an issue a friend had with his 01 Yukon Denali. Ended up being a small positive wire coming from battery and that wire went under the battery tray. The wire got pinched and was either grounding out or losing connection. He had that wire replaced and all has been good.

  • 2 weeks later...
socrates Enthusiast

socrates

Posted
  • Author
Posted

Yes, Here's the update. My local mechanic took it in again checked all the grounds and was unable to reproduce the dying so he gave it back to me on monday evening. I drove it for 3 days (short trips) and couldn't get it to happen again, however on the 3rd afternoon it randomly acted like it was going to die again on my way home but it didn't. So I let it sit for the weekend took it back to the same mechanic he hooked it up to his scanner and all he saw was an evap code. He said he didn't see any problems and was going to give it back. He then mentioned that he had an errand to run about 45 minutes away and asked if I'd like him to hook up his scanner and drive it to and from that errand. Well that's what he did and it died on him on the freeway. He was able to get over and it turned out that the code that the computer threw him was a crankshaft sensor code. So he replaced the crankshaft sensor and hopefully that's all there is to it and no more issues. We shall see...

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