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I have a 1997 i did a 411 swap on and i can flash the PCM no problem. But once its been flashed once..
You have to pull the battery
Wait 30 seconds
Hook battery cable back up
flash peramiters
Its annoying but not impossable. Id rather not have to do it. I always disconnect my loging tool software befor attempting to reflash the PCM.
Any Ideas what may be causeing this?
Thanks,
HKH
Do you have the IGN power wired up correctly? Eg, when you key off does the PCM still have +12V battery but the +12V from the IGN switch is no longer present.
When i turn the key on the fuel pump primes. Which indicates to me that the power on the PCM is shutting off like its supposed to. (if thats what your getting at) The Swap was performed exactly per Lextech's spreadsheets.
It always stops in the x of 5 stages and never makes it to actually pushing over the tune configs.
i can copy a log at some point for you (the connection log)
I've done the swap with no issues. Even if your careful it's easy to mis pin one wire.
If you've done a full flash it should not be needed again, just calibration. Doing full flash in vehicle can cause issues when other modules loose connection to mothership! I've only done full flash on bench, don't really want to find a way to turn PCM into a doorstop...
im not doing a full flash... im only "Program PCM with current loaded calibration"
I only did a full flash once to get started. Ill prolly switch to cos5 before putting the charger on there.
I checked the pins 3 times and had someone else check them after i was done. not that its not possible but its not probable.
Sure sounds like what is mentioned above ^^.Quote:
Originally Posted by GMPX
Lextech files are accurate, if there's an issue he updates, it's been done so many times I'm not sure he could find any other issues? I had one wire in wrong plug on mine and it took three shots to find it, humans aren't real brite you know!
You got wiring files from him right? Not old ones from a freind? Correct for 97? There are differences in 96, 97 and 98-00...
Could there be some wiring changes to vehicle? One thing I could think of, would have to be verified by GMPX is serial data line, from ALDL port from the 97 vehicle to 2002 0411 PCM? There's 2, one ties to other modules, not sure what was going on in 97?
Yea I did. I'll pm him and get another copy and go the it all again. But the thing that gets me is that the fuel pump primes when you turn the key forward. It wouldn't do that if the pcm was already on....
Maybe I'm wrong.idk
You've got the right train of thought. But there are more then one constant 12v and Ign on 12v wires, then 2 possibly serail wires, one Purple and one Orange, I don't have 97 diagrams...
Also when I did mine I marked the four wiring harness going to four PCM plugs, so I knew what Vortec wire came from what Vortec plug. If you didn't do that then re-checking is much harder! Could have a... say Purple/White from Red PCM, mixed with Purple/White from White PCM. Now that all four Vortec PCM plugs are gone you can't be sure! I mis pinned one VSS wire and got a ABS light, without marking the four origanal harness It may have taken days to find. Point is if your checking a Purple/White, is it the correct Purple/White? There may have been a Purple/White in each of the four Vortec PCM plugs.
Look at your diagram for Serial Data, my 98 Votec says (Primary) purple wire, Also has a Brake Signal wire next to it that is Purple!
Alright so if the engine has been run at all for the x hours it seems that it reports unknown state when attempting to flash.
So it may be a wiring problem..... Any way we could know which pin? i really dont want to track this thing down.
Are both of the wires you mention purple with no stripes?
Thanks
Verify with test light or meter that (Blue)C1-19 and C1-75 is switched 12V+ and C1-20 is Battery 12v+. I bet C1-19 and C1-20 is flip flopped. This is according to the 2002 van pinouts.