I just had a Yank 3000 converter installed along with an FLP Level 4 tranny and 3.15 rear. After the install, the torque converter would not lockup at highway speeds. After about 50 miles being put on the new setup, it started to lockup like it should around 50 - 60 mph. It was doing fine for a while and now its started having problems again. Sometimes it will lockup and then disengage while at a steady speed and on level ground. At one time, it threw an 1870 code which is what I understand to be having to do with transmission slippage. After doing a search here on the forum, I found several people had the same issues but I haven't found any responses that came up with a definite cause and cure. One theory was the torque management which is a computer issue. I'm wondering if this problem is fixable through a change in the programming. All I've got is a Hypertech programmer which is what I used to program for the 3.15 gear. I left all of the other settings stock with regards to shift points and firmness. The level 4 tranny has a shift kit in it already. Will this continuous slipping in and out of lockup hurt anything and has anyone who had this problem in the past fiound a cure?? Thanks! :cheers:


[Modified by MikeyD, 10:58 AM 5/27/2003]

 

When your PCM sees the high stall from the TC, then it throws the 1870 code as it thinks the tranny slips.
Along with the code, the PCM doesn´t let the TC to lock up.
If you clear the code, you´ll see the TC locks up for a while.
If you have LS1 edit you can programm for that.

Michael

 

I just got off the phone with Mike at Yank and he said the problem could be fixed through reprogramming. He also mentioned, however, that the FLP's may be set up with too high of line pressure that may cause problems as well. He had mentioned that it may not be a good idea to run the FLP tranny with an 1870 code set and the computer running in backup mode. I'm going to check with Chuck at FLP on this. Anyone else have this issue? As mentioned before, I haven't seen anything recent on this subject. Thanks! :cheers:

 

I just talked to Chuck from FLP and apparently the simple fix is use LS1 edit. As to excessive line pressure, that is not an issue with these trannys as they use a vacuum modulated system. Chuck is a great guy to talk to. Very helpful ..Thanks Chuck! Now to find an LS1 edit around here :rolleyes:

 

That´s what I said.

I have an FLP since three years now.

And don´t ask YANK about FLP :D

As Chuck said....you now have shift firmness via vacuum, so it´s no problem if you have the 1870 code set.
Yank trannies would have a BIG problem with that.
As they still have shift firmness via PCM signal, the 1870 code sets the shift firmness to maximum and that can be a problem for stock trannies and YANK trannies.
I have ssen a lot of YANK trannies breaking because of this.

But again, it´s no problem for the FLP tranny.

Just get LSI edit and tune it out!!

Michael

 

Thanks Michael!
Last thing I wanted to do is blow a new tranny and/or TC!

 

I am completely surprised that you require any programming beyond simple gear scaling for a Y3000 and 3.15s. Sure, you might want to do some fine tuning but you should not have to program (beyond gear scaling) to avoid P1870s.

FWIW, P1870 only runs under conditions when the TCC is expected to be locked and differences between engine speed and transmission input shaft speed at a minimum. A high stall converter all by itself won't trigger this. If your TCC is engaged but engine speed isn't pulling down you're not locking up for some reason. Things like glazed surfaces and low fluid levels are frequent culprits.



[Modified by ToplessTexan, 11:45 PM 5/27/2003]

 

The only thing I found was the tranny fluid level was down about 8 ounces. (Just had the tranny, TC and gears installed) Surely, that couldn't be enough to cause problems. Chuck at FLP said that when he installs the Level 4's in the C5's, he always tunes the TCC out or at least reconfigures it so that the 1870 doesn't pop up. Funny thing is that I had this same code pop up with the old tranny and stock converter in, come to think of it. Ummmmm! Possible cable problem coming out of the PCM?? Anyway, I haven't drove the car since adding that little bit of fluid to it. I doubt its going to make that much difference. Whats dtrange is that when I first start out after the car has been sitting there, the TCC works fine. Then after a while at highway speeds, it kicks out and then stays out. Sometimes it will do this and never set a code. :rolleyes:

 

I think thats exactly where your problem is. Those transmissions are extremely sensitive to proper fluid level. I am running a 3;15 and a Yank 3000. When it was installed the tech did not fill it properly and I had problems. It was down about a half quart or so. He refilled it and my problems went away. Just make sure that the car has been driven and the transmission fluid is hot/warm. I think you will be suprised that its something as simple as that.

 

He´s correct!!
Keep your tranny fluid lever up !!! :yesnod: :cheers:

Michael

 

Get your PCM programmed for the convertor. I had a Yank 3000 in mine and the P1870 and line pressure destroyed the convertor. This was with stock programing and stock tranny. :thumbs:

 

You wouldn't think so, and yet...

Do a search for c4c5specialist's take on the primary source of tranny problems he sees.

If you're seeing P1870 (and have verified any gear scaling programming changes are correct) you have an issue. It will not happen with a properly functioning lockup converter. You should not need programming to fix this unless your converter requires increased line pressure for the TCC to function properly. (And I think that's a converter design or manufacturing problem, there are too many designs out there that don't.) You don't have to take my word for it, there are like billions of F-bodies on the net running stupid high stalls w/o any form of programming that don't get these codes.

I fully expect you can look forward to an easy fix. :)



[Modified by ToplessTexan, 9:56 AM 5/29/2003]

 

:iagree: My sons F body had several convertors with no problems whatsoever. I have heard that its a specific problem when changing stalls on a C5. It seems we have 2 speed sensors in our A4's to measure slippage where the f bodys only have one. GM designed our programming alot tighter specifically to the slippage designed into our stock convertors. This does not allow the use of higher stalls without tweaking the program. :cheers: :thumbs:

 

I was assured by Chuck at FLP that the 1870 code should not present a problem as far as increased line pressure goes because the Level 4 tranny operates on a vacuum-modulated system. Apparently, when the P1870 code is set, the PCM sends a signal to the tranny to go to max line pressure and that is what blows the converter and even the tranny itself if it's already set up for a higher line pressure. But the level 4 tranny does not rely on the PCM signal to control line pressure, instead it relies on vacuum. ( Has anyone else been told this?)

I added a few ounces of fluid and this morning it threw the 1870 code one time early on a 20 mile trip. I reset the code while driving and the converter locked up fine and stayed locked up for the rest of the trip. It just seems random as there appears to be no particular condition when it does it. I might check the fluid level again because when I added the fluid I stopped when I thought there were some fluid dribbling out of the fill hole. It might have just been some residual around the hole.
regardless, it sounds like a fix would be the tuning but I'll have to get a hold of a LS1-edit for it. The hypertech doesn't allow for any TCC parameter changes.


[Modified by MikeyD, 10:24 AM 5/29/2003]

 

Your correct about the vac controlled level 4 from FLP. Chuck told me the same thing & showed me the new vac line that he installed for it. I have the same TC you do (SY3000) & have the same random P1870. I used LS1Edit to raise the 4th gear TC lockup from 36mhp to 50mph & 3rd gear from 26mhp to 40mph. That helped some. Now the code doesn't set as often. I went from 273 gears to 342s & used the LS1Edit (actually Chuck at FLP did) scaling for this change & still set the code. I did fine tune the WOT shift points but the scaling is as LS1Edit has in it. Chuck did my install so I don't think its a fluid level issue. He explained to be sure its filled to the correct level when I change the fluid later on, as it is very important. If LS1Edit can "tune" this problem out (short of deleting the code) what exactly do we need to change? Any other ideas? :cheers:


[Modified by newberd, 11:05 PM 5/29/2003]

 

If you guys are seeing 1870s, something is not right. The only sensors involved in measuring slippage are the tach signal and the VSS signal. Values are derived from this (specifically a bunch of intermediate values are derived from VSS) and engine speed (from the tach) is compared with transmission input shaft speed (derived from VSS.) This difference is called TCC slip speed and is an observable OBD-II parameter. It's this value that cues the 1870 DTC but the test only runs when the TCC is engaged. The idea is to rule out the converter as a source of loss (by assuming the TCC is working properly) and determine if there is another mechanical component not functioning properly. All this parameter really tells you is an overall "loss" between the engine and the output side of the diff.

It would be helpful if you guys having problems could collect some OBD-II data to see what kind of TCC slip speed values you're actually seeing. I guess I would lean toward TCC problems (glazing, not able to stay engaged, etc) but would be easier to speculate more usefuly with some more data.

You can make the P1870 go away w/o disabling the code if that's really what you want to do. I would not recommend that as I suspect you have mechanical rather than programming issues. Having lived with P1870s myself though, I can understand the interest in a short term band-aid. :D If you go to the Transmission Diagnostic item of the main Edit menu, there are some test parameters that you can adjust. You can raise/lower the "torque converter slip" values (horribly misnamed, but that's another issue) such that the code doesn't ever throw. (This feature was first added as a workaround when the gear scaling was still broken for C5s and TCC slip speeds were typically like 7-800 rpm with the TCC locked.) You can most easily identify the limits you want to use by observing the OBD-II data I mentioned above. For this kind of stuff I always collect engine speed, vehicle speed, transmission output shaft speed, transmission input shaft speed, current gear, and TCC slip speed. Using this data (collected over a range of road speeds and gear) and knowledge of tire size and gear ratio, all kinds of analysis related to the relationship between engine speed and road speed can be done (in particular it's useful for understanding your converter and shift points.) I'm digressing now... Please be careful thinking programming can fix this. Programming can only hide or avoid the underlying issue.

I will try to keep an eye on this thread today.



[Modified by ToplessTexan, 9:22 AM 5/30/2003]

 

Thanks for insight ToplessTexan. I tried AutoTapping the perameters you mentioned on Chuck's advice but could never get the P1870 to set when I was logging. I don't feel anything differant in the car or even see the tach change when the code sets as some have indicated. Currently I see the code about once a week. Chuck said he has seen this alot specifically with Yank. He sells the Vigilanty and doesn't have the code problem. I didn't have problem before the mods - Level 4 tranny, SY3000 & 342s. I don't know the technical part of the TCC or if is replaced during these mods.

Can I AutoTap these perameters without the code being set during logging & get an idea the slip percentage?

MickeyD, I don't want to take over your thread but I think we all can benifit from the info. :cheers:

 

Thats ok Newberd. I don't have time right now, but when I get home later this evening, I'll study the comments already made and try to get some readings. I assume I can use Autotap to get some info, right? I sure hope I don't have to drop this tranny again!! :eek:

 

I'm back home still don't have time to check these issues. Hopefully before Monday. Just thinking about it though, its hard to believe that Newberd and I have bad yank 3000 stall converters and we just happen to be running the same tranny. I think there has to be some type of compatability issue between an FLP level 4 tranny and Yank converters. Maybe the FLP runs too high of line pressure for the Yanks which if that was the case, that could be easily taken care of...........Or am I just hoping it really isn't an issue with the converter! :sad:

 

This may be a hint. The lack of increase in RPM when the code trips (as if something let go) suggests that the TCC wasn't locking properly. As MikeyD pointed out above, the PCM's commanded line pressure will be ignored due to FLP's vacuum modulator setup. As a result you shouldn't expect the sudden increase in shift firmness that folks normally see with P1870. Long, slow grades at moderate speeds are great for testing.

Sure, I think it would be an excellent idea to get a good feel for what "normal" operation is like. It's beginning to sound a little like you'll also want to monitor whether or not the TCC is being commanded on and whether or not you're seeing an RPM drop as a result. If it's commanded on but you're not seeing an RPM drop, you would seem to have some sort of mechanical issue. I forget the parameter name in AutoTap but seem to remember it being somthing of a pain and having to look at a duty cycle value rather than a binary on/off value. In EFILive the candidates are TCC MODE, TCC DC, and TCC APPLY TIME. If it's not ever being commanded on, that's a PCM issue.

I'll tread lightly here regarding brand issues and just offer that I have two Yanks and am planning on buying an FLP tranny later this summer. :) There are lots of folks here with similar setups, hopefully that's encouraging.