Well driving today i come to a red light and try to start going again and it feels like i have no power and the tranny is slipping, then the check engine light came on so i turned it around and limped it down to the auto parts store to get the codes read. I can manually shift just like everyone else can and its fine.

I got the P0740 & P0785 codes twice for some reason. I read a lot about them on here and saw that it could either be a Fuse, the ignition switch, the wiring harness, or the solenoid itself.

So im making another thread on this just so people have more info on what possible problems are, and also in hopes that some people have some input.

All help is greatly appreciated!

Edit: well that 10 amp fuse is alright, so that tells me that the wiring harness should be alright and not shorting out? And also, if its the ignition switch causing it, would the tranny still go into limp mode like its doing?

Edit again: I should also note that when i took my truck into the shop to have them read the temperature two days ago when i was having thermostat troubles, none of their scanners would hook up to my computer. And also, Sometimes when i turn my key to run my check engine soon light wont come on. Could this be leading towards my ignition switch??

Edit for a third time: I took it out for a spin and everything was fine.. even after i let it get up to running temp. I had no problems starting up hills from a stop or anything. For a second it felt like it may have been slipping but it could have just been me. and also when i got back i could kinda smell burnt clutch or maybe burnt mud. but when i hunted around under the truck for it i could smell anything else. So what should i do? go get the codes cleared and see if they come back??

P0740-Torque converter clutch solenoid x2
P0785-Shift timing solenoid x2

 

Well i have a feeling this problem has to do with this lovely PCM i got from wait for me tune... I am going to put in my stock one and see what happens.

I read the two posts made by swartlkk and the common theme on them was the VCM (or also PCM?) So thats what im leaning towards

 

Well a little update...

i didnt put in my stock PCM because the problem wasnt coming back at all so it thought it was fine. But the other day my check engine light came on and my transmission went into same mode, so i went and got the codes cleared and it was fine for another two days accept now its throwing the P0758 and P0753 codes along with the P0740. So im nt sure what happened with my P0785 code but these two new ones came up. (and they all came up twice)

So im going to try the stock PCM and see what happens then my next guess is the ignition switch but i would really like to figure out a way to test the ignition switch before i replace it. And im really hoping that these codes are related to the same issue.

Opinions are greatly appreciated!