Torque Management

[JohnRXL]

Ok I know this is not a GM truck, but my 06 Chev 3.9VVT Uplander has some serious slippage issues when shifting from 1st to 2nd when hard on the gas, is this the torque management that everyone with the newer trucks have removed to better the performance?
If so where could I go to have it removed if it's even possible on the van.

[omegafiler]

If that is the way it's suppose to shift, then it very well may be TM. But normally TM just pulls timing (reduces power) before up shifts so it doesn't slam into gear. So if it really is "slipping," that wouldn't be TM's fault.

I've also never driven one of those, so not sure what is "normal" for those tranny's. I'd take it to the dealer and have a mechanic or service manager go for ride first to see if something is wrong. It may be as simple as a PCM update.

[AlienTranz]

What trans do you have in there? I have been seeing quite a bit of early failures coming from these 04 up 4l60e's
They are fixing quite a bit of transmissions with re flashes. The only thing that the computer has control over that would cause a slip is the electronic pressure control, and they are tuning them down as low as possible to make a "comfortable shift"

[mgrotel]

im having 100% of my TM removed

[omegafiler]

Just be careful removing all TM. Some vehicles may not like having it all removed. Different vehicles will react differently to making changes to TM - you may have shift lag, power loss on up shifts, very hard shift, etc.

Thats why most custom tunes typically don't remove any more than 75-80% of TM.

Just something to keep in mind.

[mgrotel]

shift lag?

[JohnRXL]

If that is the way it's suppose to shift, then it very well may be TM. But normally TM just pulls timing (reduces power) before up shifts so it doesn't slam into gear. So if it really is "slipping," that wouldn't be TM's fault.

I've also never driven one of those, so not sure what is "normal" for those tranny's. I'd take it to the dealer and have a mechanic or service manager go for ride first to see if something is wrong. It may be as simple as a PCM update.
Your explanation on the way it shifts sounds closer than mine, it seems to hold back just before it slides smoothly into the next gear.
So can I get a certian % of this TM removed?

[JohnRXL]

What trans do you have in there? I have been seeing quite a bit of early failures coming from these 04 up 4l60e's
They are fixing quite a bit of transmissions with re flashes. The only thing that the computer has control over that would cause a slip is the electronic pressure control, and they are tuning them down as low as possible to make a "comfortable shift"
I have absolutly no idea what's in that van, but I'm sure it's not any pre-mature wear.

[AlienTranz]

I have absolutly no idea what's in that van, but I'm sure it's not any pre-mature wear.

Check with the dealer see if they have a reflash for a slight slip on the 1-2 shift under load, if not you can always crank the e.p.c screw in 1/8 of a turn, that will give you a little more e.p.c. pressure.

[JohnRXL]

Check with the dealer see if they have a reflash for a slight slip on the 1-2 shift under load, if not you can always crank the e.p.c screw in 1/8 of a turn, that will give you a little more e.p.c. pressure.
Thanks, but what is a e.p.c. screw and where is it?. Is this something that can be done without having to worry about the warranty? Or will the dealer do it for me if I ask?

[AlienTranz]

Thanks, but what is a e.p.c. screw and where is it?. Is this something that can be done without having to worry about the warranty? Or will the dealer do it for me if I ask?

I don't see how it could void the warranty, cuz there would be know way of telling you did it, other than a little firmer shifts, but all they would do is either replace the solonoid, or warranty your trans. Assuming you have the rear wheel drive 4l60E you would need to drop the pan, and when the pan is off you'll have to remove the e.p.c. solonoid which is located directly under where wiring harness comes into the trans. It's just one 8 mm bolt. Then you'll see a tiny torx screw on it, and you'll need to turn it in, like you are tightening a bolt. 1/8th of a turn is all you'll really want to do, any more and you might have too firm of shifts. If you don't mind firm shifts you can go 1/4 turn, but you don't want to get carried away. Then just put it back and plug it in. I have a feeling that if you can get it to act up for the dealer, they will either replace your trans or reflash your computer. Most dealers at least around me don't get to involved in tranmission repair, so if a reflash doesn't work then they replace the unit.

[justin]

Check with the dealer see if they have a reflash for a slight slip on the 1-2 shift under load, if not you can always crank the e.p.c screw in 1/8 of a turn, that will give you a little more e.p.c. pressure.

Making that change would only be a very temporary fix. The increased line pressure would cause the shift to occur faster than the defined "Desired Shift Time" in the transmission. As these firmer shifts occur, the PCM would measure the amount of time a shift takes to occur, see that the shift is occuring faster than desired, and lower the commanded line pressure as a result.

[AlienTranz]

Making that change would only be a very temporary fix. The increased line pressure would cause the shift to occur faster than the defined "Desired Shift Time" in the transmission. As these firmer shifts occur, the PCM would measure the amount of time a shift takes to occur, see that the shift is occuring faster than desired, and lower the commanded line pressure as a result.

I think your thinking of a transmission with adaptive shift learn. As far as I know the 4l60e doesn't have that capability. I've never seen one throw a gear ratio code. For the ecm to know how long a shift takes it would have to at least have an input sensor on the transmission. I still haven't seen a input speed sensor on a 4l60e. For example 1870 is a general code, it can mean anything. It's a performance code set by the computer that detects a slip, but it can't tell you what is slipping, like for instance a front wheel drive that 1870 code will be a gear ratio code first second third or 4th or even lockup. Those transmissions are capable of changing the timing on a shift.

[justin]

I think your thinking of a transmission with adaptive shift learn. As far as I know the 4l60e doesn't have that capability. I've never seen one throw a gear ratio code. For the ecm to know how long a shift takes it would have to at least have an input sensor on the transmission. I still haven't seen a input speed sensor on a 4l60e. For example 1870 is a general code, it can mean anything. It's a performance code set by the computer that detects a slip, but it can't tell you what is slipping, like for instance a front wheel drive that 1870 code will be a gear ratio code first second third or 4th or even lockup. Those transmissions are capable of changing the timing on a shift.

The 4L60E absolutely does have adaptive shift learning, and yes, that is what I was talking about.

[AlienTranz]

When did they come out with adaptive shift strategy?
Even if that 06 chevy had adaptive shift strategy It's been gone for 2 months now and it's under 3 years 36k of my warranty, so I'll keep you posted if something goes wrong, but until I hear back i'm still under the impression that the shift kit is still working like it did when it left my shop.

[justin]

When did they come out with adaptive shift strategy?
Even if that 06 chevy had adaptive shift strategy It's been gone for 2 months now and it's under 3 years 36k of my warranty, so I'll keep you posted if something goes wrong, but until I hear back i'm still under the impression that the shift kit is still working like it did when it left my shop.

As early as 98, but probably earlier (I don't have the software to go earlier).
Even with it in place, it will still shift better than stock. There is a limit to the amount that the adaptive shift learning functions can adjust the pressure.

[JohnRXL]

Went to the dealer Sat. and they said they WILL NOT touch the tranny for any reason unless it completely fails or just needs some simple service:dunno: Nice.
According to the service manager they all shift soft at high RPM.

Still looking into getting some of the TM removed.

[AlienTranz]

Went to the dealer Sat. and they said they WILL NOT touch the tranny for any reason unless it completely fails or just needs some simple service:dunno: Nice.
According to the service manager they all shift soft at high RPM.

Still looking into getting some of the TM removed.

I find this really unsettling. I really don't think general motors wants there dealerships representing them like this. I mean if you have a legitimate problem and you know about it, why do you have to wait for complete failure before something is done about it. This is why domestic manufactures are losing busniess to Toyota. Toyota has always been known to go the extra mile to satisfy their customers. I don't see what the big deal is. How hard is it to come up with a reflash that commands a little more pressure for the 1-2 shift. All they have to do is explain hey you may feel a little firmer of a 1-2 shift, but it will get rid of the slip, and i'm sure no one is going to say actually i'd rather it slip.

[JohnRXL]

I find this really unsettling. I really don't think general motors wants there dealerships representing them like this. I mean if you have a legitimate problem and you know about it, why do you have to wait for complete failure before something is done about it. This is why domestic manufactures are losing busniess to Toyota. Toyota has always been known to go the extra mile to satisfy their customers. I don't see what the big deal is. How hard is it to come up with a reflash that commands a little more pressure for the 1-2 shift. All they have to do is explain hey you may feel a little firmer of a 1-2 shift, but it will get rid of the slip, and i'm sure no one is going to say actually i'd rather it slip.
I'm going to go to a reputable tranny shop (Mr.Transmission)in town here and see what he has to say about it.
The biggest thing with this slippage bulls**t is when I have the van fully loaded for camping and pulling the camper I don't feel like being stranded because the damn tranny just went.
Atleast there is a cooler already installed from the factory but the trailer hitch was something that did not come with the trailering package:whatever:

[Pauly]

As early as 98, but probably earlier (I don't have the software to go earlier).
Even with it in place, it will still shift better than stock. There is a limit to the amount that the adaptive shift learning functions can adjust the pressure.
1996 and 1997 Vortec trucks also have adaptive learning. I had mine switched off when I installed my Trango Stage 2 kit.

I wish EFILive did the 96-97 trucks, they do the 98-00 black box PCM'ed trucks as you allready know .

peace
PAuly

[justin]

1996 and 1997 Vortec trucks also have adaptive learning. I had mine switched off when I installed my Trango Stage 2 kit.

I wish EFILive did the 96-97 trucks, they do the 98-00 black box PCM'ed trucks as you allready know .

peace
PAuly

I figured they would have it too, just don't have conclusive evidence.

As I udnerstand it, 96-97 will be available at some point in the future.

Justin

[mgrotel]

1996 and 1997 Vortec trucks also have adaptive learning. I had mine switched off when I installed my Trango Stage 2 kit.

I wish EFILive did the 96-97 trucks, they do the 98-00 black box PCM'ed trucks as you allready know .

peace
PAuly

did you have to have it switched off through the tune or how did you turn it off?

[omegafiler]

Take it to another dealer and have 'em go for a ride. Let them tell you if they really think its normal or not. If they still think its perfectly fine, then you may want to find another identical or at least similar vehicle and see how it shifts. Use that for comparison.

The problem is... if another vehicle drives the same way... the only hope is that it you can tune it to remove some TM or at least increase line pressure.