Need help with standalone harness.
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Teching In
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Need help with standalone harness. Hey guys. So as I've said in 4 other post I have a 2010 chevy 3500 with an l96 engine, 6l90e transmission and a e38 ecm. I ordered a standalone harness from fleebay while the engine will run on it I'm getting 23+ codes. Yes 6 of them are evap which was supposed to be tuned out. I brought chassis and ecm and harness to tuners. They shut off vats and starter relay and they did the rear o2 sensors and evap but for some reason those didn't stick. So no the rear o2 sensor codes are on. And evap is on. Well after getting everything hooked back up I've got a hand full or codes! 26 to be exact. Some are permanent. Some are pending and some are history. No matter what I do they all come right back. So... I'm wondering being that most of these codes are like 1 is knock sensor bank 1 circuit low.... well I put new sensors in and checked plugs. Still there... crank position relearn is there.. new sensor installed still there.. throttle pedal sensor circuit e low... and circuit d low. Then tonight randomly as I'm testing power steering I get p0960 .. ecm voltage pcm relay sense circuit HIGH. What in the actual FU** is going on here!?!?!?? I'm not a quitter but I'm so sick of firing the parts cannon that I'm about to send it to the scrap heap. I've rebuilt ALL POWERS AND GROUNDS! all connections are solidered and shrink tubed. I just don't get it. PLEASE HELP ME!
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After doing a bunch of reading about these codes and the fact the evap and rear o2 codes were disabled but still there on dtc I'm wondering if ecm isn't taking a dump. I've got a total of 32 codes. Alot are duplicates. I have a mechanic coming over today and hopefully he can scan it and delete all the codes and then we will go from there and see what the next step should be but I can get a new ECM reprogrammed in everything for $200 plus shipping. So before I go buying a wiring harness I'm gonna have this one checked and if that turns out to be the problem then I'll have to buy a new ecm.
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Because I tried making my own on the last 6.0l I had and ended up not feeding 2 injectors and had several sensors say "low voltage " and when i ask for help people cant point me in any sort of direction so I bought a plug and play harness that only took modifying for the transmission but I'm pretty sure I got that squared away
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the truck used to be a 2010 chevy 3500 express cutaway mini bus. I pulled the body off to put my 53 body on the mini bus chassis... I did keep the oem harness but it had all sorts of stuff I don't need like evap and rear o2 sensors and a few more so instead of cutting the harness up and taking a chance on messing it up for a second time I opted to buy a standalone harness. Lots of people that do ls swaps buy standalone harnesses.its just alot easier and alot cleaner. Another thing is the oem harness was made (loomed and wire length) to into the driver side of the bus body firewall. I can't have that. Needs to be on passenger side so I can mount the ecm under glove box.
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For the issues you are having is exactly why I always use GM factory harnesses. I can open up a harness and remove all the wires I do not need. In addition I can lengthen, or shorten, any/all wires so that I can place the PCM anywhere I want and it will work. I've never personally bought an after market harness but have bought several projects that had them installed when I got them.. The amount of re-work to fix issues, and put the PCM where I wanted was the same as starting with a used GM harness.