Couple 4L60E questions
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 800
Likes: 3
From: Port Orange FL
Couple 4L60E questions
I have a few things I am not happy with regarding the operation of my Transgo equipped 4L60E and I am wondering if these things can be fixed by programming or if I need another solution.
1. When I launch it if I get wheelspin and try to feather the throttle to control it the tranny upshifts into second on me ruining the run.
2. If I try to hold it in low and manually shift it there seems to be a delayed reaction time when I move the shifter causing it to often overrev and hit the limiter.
3. (may be related to 1.) The shifting seems to not be linear. IE at light throttle it shifts as it should, but if I step down on the pedal somewhat it seems to shift too soon. Like it is not reacting to the additional throttle input. It shifts fine at WOT.
4. I would like to be able to have full manual control over the gears. IE be able to hold it in 2nd down a twisty back road or on an autocross course. Also be able to have it upshift or downshift instantly when I move the shifter rather than have it seem to continue to have a mind of its own, sometimes waiting to do what I tell it to. But I would also like to still have it shift normally when just driving it around. How do I accomplish this?
Thanks in advance for anybodys input.
Roy
1. When I launch it if I get wheelspin and try to feather the throttle to control it the tranny upshifts into second on me ruining the run.
2. If I try to hold it in low and manually shift it there seems to be a delayed reaction time when I move the shifter causing it to often overrev and hit the limiter.
3. (may be related to 1.) The shifting seems to not be linear. IE at light throttle it shifts as it should, but if I step down on the pedal somewhat it seems to shift too soon. Like it is not reacting to the additional throttle input. It shifts fine at WOT.
4. I would like to be able to have full manual control over the gears. IE be able to hold it in 2nd down a twisty back road or on an autocross course. Also be able to have it upshift or downshift instantly when I move the shifter rather than have it seem to continue to have a mind of its own, sometimes waiting to do what I tell it to. But I would also like to still have it shift normally when just driving it around. How do I accomplish this?
Thanks in advance for anybodys input.
Roy
Burning Brakes
Joined: Aug 2007
Posts: 769
Likes: 0
From: Cincinnati OH
The 4L60E is an electronic transmission. One of the big influences of how and when it shifts is the throttle position sensor. Your issues could be two fold.
#1 if the TPS does not read correctly, the transmission will never shift as it should. You should have around .7 volts at full closed and 4.5 volts at WOT.
#2 On your power runs that you say it shifts too soon, the car could see that you have backed off the throttle, and at a "normal" throttle angle, it may determine that it is time for the shift.
I do not know about the corvette for sure, but on my regal ( other gm product ) a type of interface product is made, making the car read WOT at any throttle angle above 75%. That may help correct your issue with the premature 1-2.
Hope this helps steer you in the right direction.
Mike
#1 if the TPS does not read correctly, the transmission will never shift as it should. You should have around .7 volts at full closed and 4.5 volts at WOT.
#2 On your power runs that you say it shifts too soon, the car could see that you have backed off the throttle, and at a "normal" throttle angle, it may determine that it is time for the shift.
I do not know about the corvette for sure, but on my regal ( other gm product ) a type of interface product is made, making the car read WOT at any throttle angle above 75%. That may help correct your issue with the premature 1-2.
Hope this helps steer you in the right direction.
Mike
Racer
Joined: Jul 2007
Posts: 281
Likes: 2
From: Mount Vernon Indiana
I'm not saying that the symptoms are suggesting a TPS problem just that the wide range of throttle to kick in "WOT mode" is normal. Not sure if 75% is normal, but it may be 85% or so.
