The resistors run in parallel. It will be approx 60 ohms. If anything other than that you need to perform some additional tests based off of the resistance that you read with your DVOM.
On more advanced CANbus issues I use The GM Data Bus Diagnostic Tool. This tells me if all the modules are reporting when pinged. Works great but your case is a simple one.
oK I got the 60 ohms at the dtc and read it and it read the complete thing with the t42. Now do i reliscense it and do the vats or go and try to find a program for the t42 to run a 4l80? Here is the file it read.
STOCK Z28 WITH T42 DON'T ERASE!!!!!!.hpt
Thanks, Tody
Was your new ECM programmed with the VIN that was already licensed?
Hardware serial will be different since it's a different ECM, it'll have to be relicensed no matter what.
Yes, you can fully program a T42 using only HP Tuners write-entire. But, you will have to also spend two credits to license the file you write to it. Getting it done with SPS before you license the ECM/vehicle will cost only two credits total.
I don't recognize or have a lookup to tell what that TCM OS 24246720 is from, but based on others I have it's likely going to be 2010 or 2011, which is on the wrong side of the breakpoint for a 2007 ECM OS.
So the vette pcm and the t42 will need 4 credits and will it automaticalley do that or do i have to do something special?
Thanks, Tody
You are doing a better job of keeping up with the my/new/old/it/etc PCM/TCM than I am. A lot of interpolation having to go on in these threads.Originally Posted by blindsquirrel
ok so i ges i need to unhook the tcm before i do the vats and liscense stuff correct?
Thanks, Tody
I think it came from that 09 impala or possibly a 2010 trailblazer i honestly can't remember.
Thanks, Tody
Has this TCM been edited in HPT before? Because all of everything has been changed from stock for a FWD Impala. It will need a real 4L80 OS written to it, regardless.
Yeh i probably screwed up but i went in and copied stuff from a express van with a 4l80 thinking that would work.
Thanks, Tody
If i unplog the tcm and do the vats rewrite will it hurt the pcm to try and fire it up? It's been sitting so long i may need more than a tcm i shouldn't but my luck the dam rings be rusted to the cylinders. It's always something with fun stuff.
Thanks, Tody
Whether you can do it with the TCM unplugged depends on how the CAN wiring is arranged - one version it will break the whole network, other version it won't. I'd leave it attached and make sure the round 20-way connector at the trans is unplugged. Select 'do not write' for the transmission when you go to write the non-VATS file.
Probably the easiest and cheapest thing to do is buy a T42 pre-SPSed to VIN 3GNGK26K77G211058 (2007 Suburban 2500).
https://www.ebay.com/itm/173406345643
https://www.ebay.com/itm/254549422193
Licensing now and then changing the TCM later won't break the license, it's based on the VIN in the file and the ECM hardware serial (the VIN isn't stored in the TCM, and HPT has said that the TCM serial is not tied to the licensing).
Ok thanks i'm going to try to delete vats and see what happens. Thanks again for all yalls help.
Thanks, Tody
Well it will not write the vats delete on the pcm with or without the tcm hooked up. I tried it with the tcm as do not write and the harness unhooked from the transmission several times. Then i unhooked the tcm and redone the gmlan wires and still times out after it erases and gets between 4-7%. I had an old battery on charger and figured that was it so got new battery same thing. I was going to change wires to interphase but it just read it with the one i used. I dunno FML.
Thanks, Tody
Have you tried to connect the scanner and see if you get any data? You can go the route Blindsquirrel has with ordering new items, or if you have data I can off board SPS the ECM and TCM as long as the hardware matches the VIN for both.
I tried to see if scanner would show any issues but only thing it would show was fuel and transmission in special options and the diagnostic part it says no dtc's but it doesn't show anything and no pid's are coming up. Iam going to see if i have enough stuff to build a bench harness tommorow and see if it will write it that way. If it doesn't i'm not sure what to do. I had to walk away today before i lost my sh&$ on it.
Thanks, Tody
In my honest opinion you are at a point that will need SPS/TechLine Connect programming. At that point you need to find (not difficult) a VIN that is compatible with not only the hardware ECM/TCM but also the software and configuration. I think you would be chasing your tail any other way. This way you can at least start the tuning process with a good foundation
If you want to send it to me I'll see what I can do on the bench. Just cover shipping. If I have to license it, cove that. If I can't do anything with it, no charge. If you need another one, I think I have a couple on the shelf. We can talk about that when the time comes. They ain't cheap anymore.
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