TCC lock logic
01-17-2006, 09:44 AM
#1
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TCC lock logic Having flakey lockup action after converter install.
It is sometimes fine and works at the TCC table
lockup TPS/MPH. Other times it will not lock, lock
late, or lock/unlock/lock. Logs show no misfires
during the misbehaviors, and the TCC Mode seems
to be driving it (i.e. when it's not locked, but should
be locked, the Mode says "Off" and when it finally
does decide to go, I'll see a "--3--" briefly followed
by "Locked" and sure enough, it does.
So this makes me think there's some non-misfire,
PCM logic term that's in play, but I have no idea
what. I thought of the brake switch but that
seems not likely (hasn't been messed with, and
wiggling the pedal with my foot while it's flaking
doesn't "unflake" it. Trans is up to coolant temp,
175F or so.
Anybody know of "other" TCC-lock conditions?
It is sometimes fine and works at the TCC table
lockup TPS/MPH. Other times it will not lock, lock
late, or lock/unlock/lock. Logs show no misfires
during the misbehaviors, and the TCC Mode seems
to be driving it (i.e. when it's not locked, but should
be locked, the Mode says "Off" and when it finally
does decide to go, I'll see a "--3--" briefly followed
by "Locked" and sure enough, it does.
So this makes me think there's some non-misfire,
PCM logic term that's in play, but I have no idea
what. I thought of the brake switch but that
seems not likely (hasn't been messed with, and
wiggling the pedal with my foot while it's flaking
doesn't "unflake" it. Trans is up to coolant temp,
175F or so.
Anybody know of "other" TCC-lock conditions?
07-28-2006, 09:58 AM
#3
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Sort of, I bumped all the misfire tables to 32767 and it
stopped doing it. Never did figure out why the thing
would show no misfires but apparently unlock from them.
stopped doing it. Never did figure out why the thing
would show no misfires but apparently unlock from them.
07-29-2006, 06:12 PM
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Thanks. I found this thread after searching a while. https://ls1tech.com/forums/pcm-diagnostics-tuning/162767-i-just-replaced-my-torque-converter-now-unlocks-randomly-fix.html I set the activation and deactivation temps to 141 and 142 and that fixed the original problem. I don't know if it is an issue or not but now the TC stays locked through a wider range of driving. It unlocks when the brakes are applied, but it takes about half the throttle before it unlocks and it drops a gear when it does. Has anyone else found better values to use?
