Shouldnt, same pcm..... Woudlnt hurt to reflash the pcm that you knew was good with the tune for 6.0

 

Flash your original 05 computer with a 6.0 tune for an 05 truck.

Sometimes there are changes in the OS that can not be seen with tuning software. A good example is the 06-07 classic DBW tac module, pedal, and TB.

If you try to use an 05 or earlier OS with the 06-07 parts or Vice Versa, It will go into REP mode. The parts and tune must match correctly.

It is a possibility that this is what's wrong with your current setup. It may be a software mis match with the Instrument cluster or the parts on the engine.

Could also be a Vin mismatch as stated earlier.

If you can't find one in the repository, Let me know. I will see if I can supply you one.

 

Did you test the MIL control circuit between the PCM and IPC for a short to ground when it is disconnected from both? And when it is connected to just the IPC?

 

Hey Guys, so I threw in the V6 PCM and turned the key forward, then realized that for some reason his truck will NOT show the check engine light unless it is running.

So I tuned the V6 PCM to have all the parameters the V8 PCM does. I then go to start it and it cranks and cranks, and will not start. It is definietly getting fuel - but is not getting spark.

I'm not sure why it will not start with the V6 PCM. The tune is exactly the same as it is with the PCM that the V8 has been running on and even if VATS was the issue - it shouldn't be since this is the PCM that came with the truck originally.

Any tips?

 

Is the pcm seeing crank signal???

 

Yup, I checked using the scanner while cranking - Crank sensor is giving accurate signal

 

I need to find a pinout for a 4.3 pcm vs v8.... Wonder if theres a difference..4.3 uses distributor as a cam sensor and iirc the crank sensor reads off the front ofbthe crank shaft on 4.3..

 

Are you seeing cam signal too?

 

Great points. I never checked for cam signal. I will have to definitely check that.

 

FastBrick, would you know why the engine isn't getting spark w/ the V6 PCM (with a 6.0L tune flashed to it)?? I read that the PCMs are exactly the same internally, so wiring (as stated earlier) can't be the issue.

The engine runs perfectly find w/ the older PCM, only issue is the check engine light being stuck on. Not sure why the V6 pcm with the exact same tune would not want to start