Converter unlocks on itself
05-24-2006, 12:22 AM
#1
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Converter unlocks on itself When my car is in OD, doesnt happen when its in D, my car will occasionally unlock the converter when I'm crusing at a steady speed, usually about 50-55. I don't understand why this happens. Sometimes, if I play with the shifter, putting it in D then back into OD it will lock again, but if I let it go it will cruise unlocked.
05-24-2006, 09:39 PM
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Mine didn't have an SES light on... How many miles are on your car???
Originally Posted by vMaster0fPuppets
i dont get an SES light or anything. Wouldnt misfires and bad O2s set theses off
05-24-2006, 11:45 PM
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Low level of misfires will unlock the converter with
no code or light. More misfires will flash the SES
light, and set a P0300. I forget the threshold for
that but onesy-twosey is enough to hassle the
converter.
no code or light. More misfires will flash the SES
light, and set a P0300. I forget the threshold for
that but onesy-twosey is enough to hassle the
converter.
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05-25-2006, 04:16 AM
#8
Originally Posted by vMaster0fPuppets
i dont get an SES light or anything. Wouldnt misfires and bad O2s set theses off
However, now its slipping in 3rd and 4th at random times on the freeway, and the idle pressure is low, but thats another issue i think. Gonna talk to Rock-On about it.
05-25-2006, 09:05 AM
#10
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On mine it seems like there isn't enough pressure to keep it locked. It will unlock under very light throttle but stays locked with more gas. It hasn't been tuned yet and the SES lights have been on since the header install. I'm getting tuned in the next month, so it should go away.
05-25-2006, 09:28 AM
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There is a problem with some converters and stock line,
TCC PWM settings being insufficient to produce enough
holding pressure at the clutch. A smaller diameter clutch
ring needs more force than the stocker to hold the same
torque.
At light cruise, if you scan, you will see the PCM commanding
0% (!) line. The force motor table translates this to a non-
zero line pressure, but still it's stupid low. Then you take this
wimped out line pressure and sub-regulate it through the
TCC PWM (another duty cycle %) and you can slip like
mad. Worse when hot and the fluid gets thin. Hello, P1870
and hello, early clutch wear. Oh, and nothing makes fluid
heat up like a slipping converter clutch, snake eats own tail.
With gusto.
If you see converter slip up light grades like freeway
overpasses, but it's smooth (not distinct lock/unlock)
you either need a converter with a better clutch, or you
need to fix some stupidities in the brain. First off, turn
the TCC PWM off; set the minimum duty cycle to 99%
as well as the max, and it becomes "all available soft-
line pressure", not the *****-footing apply that GM
thought would save you 0.03MPG by lessening trans
pump load. If the slip was attended by a lower-than-
full TCC Duty then this might suffice.
But it didn't for me and my dainty little TCI 3000, so
I had to take down the force motor current in the lower-
line% columns to gain line pressure there. This is not a
place to clown around, but it got me through another
ten thousand miles without breaking anything, before I
finally stepped up to a better clutch system converter.
I guess I did right by going to the Fuddle "High Performance
Street" model from the base one I originally picked but
never installed (trade-up policy,
) seeing that
you (you2slo) have similar to my original pick and the
same problem I was trying to leave with the TCI.
MAF lean error or even speed-density lean error brings
a load calculation error along with it; load drives the
trans line pressure control. Before you-all go down the
trans settings road, be sure you have a clean state
of tune and hardware in these respects. A car with
positive LTFTs wants you to start at the start.
TCC PWM settings being insufficient to produce enough
holding pressure at the clutch. A smaller diameter clutch
ring needs more force than the stocker to hold the same
torque.
At light cruise, if you scan, you will see the PCM commanding
0% (!) line. The force motor table translates this to a non-
zero line pressure, but still it's stupid low. Then you take this
wimped out line pressure and sub-regulate it through the
TCC PWM (another duty cycle %) and you can slip like
mad. Worse when hot and the fluid gets thin. Hello, P1870
and hello, early clutch wear. Oh, and nothing makes fluid
heat up like a slipping converter clutch, snake eats own tail.
With gusto.
If you see converter slip up light grades like freeway
overpasses, but it's smooth (not distinct lock/unlock)
you either need a converter with a better clutch, or you
need to fix some stupidities in the brain. First off, turn
the TCC PWM off; set the minimum duty cycle to 99%
as well as the max, and it becomes "all available soft-
line pressure", not the *****-footing apply that GM
thought would save you 0.03MPG by lessening trans
pump load. If the slip was attended by a lower-than-
full TCC Duty then this might suffice.
But it didn't for me and my dainty little TCI 3000, so
I had to take down the force motor current in the lower-
line% columns to gain line pressure there. This is not a
place to clown around, but it got me through another
ten thousand miles without breaking anything, before I
finally stepped up to a better clutch system converter.
I guess I did right by going to the Fuddle "High Performance
Street" model from the base one I originally picked but
never installed (trade-up policy,
) seeing that you (you2slo) have similar to my original pick and the
same problem I was trying to leave with the TCI.
MAF lean error or even speed-density lean error brings
a load calculation error along with it; load drives the
trans line pressure control. Before you-all go down the
trans settings road, be sure you have a clean state
of tune and hardware in these respects. A car with
positive LTFTs wants you to start at the start.
05-25-2006, 10:44 AM
#12
11 Second Club
This is the explaination I was looking for. You should be a moderator or something. 
Since your post contained lots of stuff I don't fully understand yet, this is something that should be able to be tuned out, right? Also, this is a huge source of heat?
Side note: it hasn't happened much since it got hotter outside.
Since your post contained lots of stuff I don't fully understand yet, this is something that should be able to be tuned out, right? Also, this is a huge source of heat?Side note: it hasn't happened much since it got hotter outside.
