Did you clear codes after swapping to the external regulator?

 

Yeah, just removed the negative battery connection for about a minute. THink that does the trick? Don't believe you can clear codes with a scanner tool until 98.
Cleaned the connector to cylinder 5, cleared codes, and the problem persisted. Going to check the voltage going to it here shortly. Seriously playing with the idea of swapping the PCM again (I still have the other one, which has a bad volt. reg, but no other issues) and seeing if that does the trick- would be easier than ordering a single injector, waiting 5 days for it, and having to remove the fuel rail for one injector = / what sucks is these injectors are less than a year old... The previous PCM didn't throw codes for an injector issue, but did for the transmission- which is strange considering I didn't touch anything in that area and suddenly its an issue when I switch computers. Going to try digging up the warranty info to see if I can't get a single replacement for the injector.

 

Verify the injector is indeed the problem before swapping it out. You should be able to rent a 'noid lite' from your local parts store, and ensure the PCM is actually trying to pulse that injector.

 

You can clear codes on any OBD2 vehicle with a scanner. Also you fo have a battery temp sensor. Is in the battery tray.

 

Thanks! I ended up pulling the spark plug in the midst of my checking the cylinder firing issue- no issue there, but after reinstalling it the code went away? Strange, perhaps it was just a loose connection at the plug. Either way, its a relief that codes gone.

Now, I've got the codes p0753 and p1765 to deal with. Trans codes

I've replaced the trans 12V relay at the ECM and checked the resistance with a multimeter- everything checks out. Even tested the relay, both by switching them out and doing a battery/voltage test.

I've switched computers a couple times now, and noticed the two codes remain either time. So I think that rules out the PCM- I mean as far as likelihood goes?

The truck seems to be stuck in "limp mode", i.e. it starts in 2nd and doesn't seem to go past 3rd. I checked the trans fluid after leaving the truck running level for 10 mins, running through the gears a bit, and finally checked it in neutral. It seemed fairly low- just slightly above "minimal", but after going through the initial process, is that normal? Could low fluid cause these codes? I don't have any leaks, if I do, there at a crawl and not noticeable. Fluid is a nice even red color, no strange smell. ALthough, prior to these issues I noticed a burning smell after driving the truck- I'm thinking now it may have been my transmission.

I guess my final approach is cracking the transmission, checking inside there for any potential frayed wires/damage/metal shavings- checking the fluid? Then ultimately replacing every solenoid/sensor in there and hope it fixes my issue. Really irks me cause the transmission was completely rebuilt just 40k ago by the last owner-

Thanks again guys, getting ready to sell this thing before the summers up and trying to make this thing as good running as possible. Its a solid running truck, just this damn limp mode issue has got me stumped. I'm close to doing the unthinkable and taking it to a mechanic just so I can maybe expedite the process with any luck.

 

I would make sure you are getting power to the trans. I had the same thing happen to me. Turns out while doing a tune up the distributor cut a wire

 

The truck can drive/move without power to the transmission? And by distributor, you mean the cap right? thks

 

Yes, the trans will work without power, but, there won't be ANY automatic function.

 

Yep and yes