Experiencing Intermittent Lockup
#1
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Join Date: May 2006
Location: Texas
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Experiencing Intermittent Lockup
So, I posted in another thread, but now I'll start my own. My converter unlocks when it should not. The builder insists that it is something in the tune. I have the problem with stock and modified tunes. The converter locks everytime it is commanded to manually (with HPTuners), but tuner could not see the cause of the unlock.
Will someone please look at my .bin files and see if you can spot an obvious problem in the tune or data log that may be causing my converter issue?
I can't attach due to size, but I will email it.
Thank You.
Will someone please look at my .bin files and see if you can spot an obvious problem in the tune or data log that may be causing my converter issue?
I can't attach due to size, but I will email it.
Thank You.
#7
You are experiencing a misfire test failure which unlocks the converter then after awhile will let it lock(unless you cycle the key) I also have a level 4 RPM trans w/ 2800 vig in my ss. I had this exact problem when i first installed everything. basically the lighter rotating weight of the vig(inertia mass) requires readjusting the misfire test tables. you can disable it all together or raise the test limits.( i deleted it) If you want to post your tune I'll look at it.
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#12
Change all the misfire values to 32767. there are 2 tables that will need changed under eng. diagnostics/misfire. the first table already has these values.The last 2 will need changed. Flash it and drive it. If this cure your problem you can go back to the original values and just raise them a little over the stock value. this is trial and error. Leaving them all at 32767 will not run the misfire diagnostics. Most poele can feel an engine miss if one develops. Having the diagnostics work helps narrow it to a particular cylinder though. Mine are all maxed. Let us know if this fixes it.
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Don't know yet! I don't have the software and I haven't been able to get to my tuner. I'm hoping to get the car on a tech2 scanner to see if we can see the unlock signal being sent from the PCM to the tranny. I was told that this scanner can read the PCM, so it will show which of the many triggers is turning converter lockup off.
I will not forget to update this thread as I get more info. I am grateful for all of the help.
Thank you!
I will not forget to update this thread as I get more info. I am grateful for all of the help.
Thank you!
Last edited by Mister Peebody; 11-21-2008 at 01:20 PM.
#19
The tuner needs to look at misfire counts while logging and then compare that to the lockup vs. misfire tables.
Higher than stock stall converters and/or bigger cams cause the problem. This is not anything uncommon and easy to fix.
Like the others said, just raise the table values for misfires vs. lockup to a high enough number where it stays locked up.
There are multiple threads about this in the PCM Diagnostics & Tuning section.
You typically won't see a DTC from it because the factory logic is setup to unlock it when it detects a false misfire from rough roads. Unfortunately, GM didn't put too much effort in the logic and just uses a generic "unlock for any misfire condition the computer perceives is actually taking place".
Higher than stock stall converters and/or bigger cams cause the problem. This is not anything uncommon and easy to fix.
Like the others said, just raise the table values for misfires vs. lockup to a high enough number where it stays locked up.
There are multiple threads about this in the PCM Diagnostics & Tuning section.
You typically won't see a DTC from it because the factory logic is setup to unlock it when it detects a false misfire from rough roads. Unfortunately, GM didn't put too much effort in the logic and just uses a generic "unlock for any misfire condition the computer perceives is actually taking place".