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2008 Denali XL possible ECM Failure?
- Thread starter Rich Reno
- Start date
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Ok, i finally got it to show the 22124708 connection, but whenever i pick something in tech2win that has to establish communication, then tech2win just closes the window after a few seconds.
can you elaborate? is it letting you select the make/model/year, etc or do you not get that far? if it is just closing and ending the program then you might have to re install it again
It would let me pick the make, model year and engine, but despite what i tried to read diagnostics on, eventually it was just like the program closed itself and i would have to start over. I was inputting the correct vehicle info, not sure if that was the problem or not.
There should be a tech2win install from the cd that came with the vx, uninstall the one you downloaded and try the one from the disc. or just unistall it and re-install
if you get stuck anywhere in the tech2 you can hit the back button
Ok, finally had time to mess with everything and get it to actually communicate. When i go to the option to have it communicate with the modules, the ECM is listed as no comm, along with the FPCM. I tested the fact that i had communication by figuring out how to roll my window up and down. So going through all of the options and diagnostic tests that are available, i am leaning towards the ECM, as I assume that would be upstream of the FPCM?
Ok, i am a bit stumped at this point. Reading with the tech 2, i can command the fuel pump to run, it give an output limit reached error, but it will read that it has pressurized the line up to about 400kpa. I can turn over the vehicle and it will run, but the fuel pump commanded state doesn't change, and the fuel pressure just slowly drops. I have checked both grounds front and back of this location and cleaned them up to make sure that it isn't something simple stupid. The one thing that was interesting to me was that when reading all of the pins of the FPCM, pin 32 which is the power from the fuse box, reads continuity to ground, but when I remove the fuse then it reads as open. Even when I cycle the key on, it doesn't break continuity at all. Am I crazy to think that this is the source of my problem? If it is though, how does that happen, and how do I fix it? Essentially both battery wires coming into the FPCM are negative and don't change operation regardless of anything I do.
I figured out that it is just some weird thing with that pin and everything is fine. Regardless, the FPCM indicates that the engine never commands the pump to run. I got rid of the dorman module and got an AC delco one just to check. I saw some places to check the dark green/white stripe wire on the connector. The wire is fine and has good continuity through to the pin, but I am not sure where to follow that wire to? I gather from looking at the wiring schematics that it goes directly there and is just a signal wire. I can make a jumper to test this, but would need to know which wire to mess with, if someone can help?
