Mister Peebody

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.

performabuilt

iTrader: (25)

the converter cannot lock and unlock itself randomly so i would agree on the tuning the most common problem hear on this is random engine missfire

deadcities

iTrader: (4)

I had a similar problem. Turned out to be the TCC valve.

Mister Peebody

I've had the car logged and tuner saw no sign of a misfire. I have th log files if you wouldn't mind looking at them.
I also get no CEL and no codes.

performabuilt

iTrader: (25)

I can only look at screen shots as I do not have tuning software. I would actually sugest you post this in the tuning section along with you logs for best results

Mister Peebody

Thank You!

COMPRACER

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.

performabuilt

iTrader: (25)

Actually no it may not set a code. Thats a common misconception that every thing will set a code Many times things like this will not.

Mister Peebody

Okay - Well here's to a resolution to this malfunction :c hug:

Mister Peebody

ttt please

ASkipper

iTrader: (1)

You need to max out or adjust your misfire cruising cells and it will lock. Mine had the same problem.

COMPRACER

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.

Mister Peebody

I will certainly keep you guys updated. Thank you

blakern

iTrader: (9)

did it work? im having simular problems.

Mister Peebody

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!

blakern

iTrader: (9)

"Change all the misfire values to 32767"

Fixed mine!!!! Thanks to (blazin)

Hope it helps you.

calongo_SS

iTrader: (7)

This is almost definitely your problem too Mr. Peebody.

Mister Peebody

I really hope it is. Glad it worked for you!
The car is in the shop now getting scanned. I should be able to get the tune adjusted next week.

Dan Stewart

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".

omcar

iTrader: (10)

a tune cured my lock/unlock issue.