I get many calls on new installs on the 60e/65e from people who have already been tuned with trans and converters from a wide range of suppliers about this.

PO757 (2-3) shift solenoid stuck. This happens when they get converters over 2800 or higher and atsome pont this code sets, The reason as I am sure you know is the stall speed confuses the PCM since the engine rpm and the output speed are not in range,
At any rate the fix is to remove the test for this code, I ussually suggest removing the testfor PO751 at the same time (shift solenoid 1-2 stuck).

But anyway my question is since this is a very comon issue with higher stalls why do so many tuners aparently not automatically disable the test for this code?
I get peobably 10 calls a week about (limp mode and PO757) after a stall and while i dont mind the calls its can be very scarey for the owner of the car thinking something has gone wrong,
Just curious
Frank at PerformaBuilt

 

I've been through two converters (3000, 3500)
and touched maybe 20+ cars & trucks with varying
stalls and not one has thrown me this code. So I
have never tried to understand what it really is "on
about".

 

It pops up here and there and is not consistant , But it does happen and since I do tec support not only for ours units but many other peoples simply because I am always avaiable, I hear about it a few times a week, I have noticed Vince at FLT answering the same question from time to time, So I was just wondering why not just automatically do it rather than wait to see if it rears its head?
It is odd though because every car wont do it an while some will do it quick others may not do it for months and then not again for months,
But was just interested to know curiousity lol.

 

It really depends on the way the converter was designed. I know Yank got a bad rep with their ST3500 and mainly the SY3500 back in the day. It was largely due to the misunderstanding of this phenomenon. The converters were excellent units, if the code was turned off. I have experienced some converters as big as 4000 stall not throw that code. It is the ECM comparing the input shaft rpm versus the output shaft rpm, if it is out of range it will throw the code (not sure what the range is). I think the STR has a big thing to do with it. Since I no longer work at B&M, I can't test this theory.

Typically, if it comes on I will turn it off.

 

The only time I get a shift solenoid code is when I attempt to lock the converter in 3rd gear and maintain a low, but consistent speed around 30 mph. It will lockup, but clearly the converter does not like it and will lug and buck slightly. Also, the shifter is in the 3rd gear position, not Drive. I would tell anyone who receives any transmission code and has a scan tool to not delete the code right away and check the freeze frame data which includes engine load and other pertinent data. Almost always, the code can be duplicated under the same conditions. Then you can look at the information help pinpoint the root cause of the problem.

 

I have done atleast 50 converter swaps, trans builds and tunes and have never seen this issue yet.

 

Interesting I have received calls from customers of almost every converter manufacter and trans builder I am aware of over the last three years about this ,
I do know low geared cars like 373 are less likley to do it than 273 cars and I know that some cars will and some cars wont, Some cars will do it right away some not for 1000s of mile and some once in a blue moon, Just seems to me that since it can and does happen why not turn it off as a precaution, In reality if the solenoid sticks without the code all will happem is the trans will stay in second and not up shift but not set limp mode either,
Its not so much I am saying every car needs it but its the fact that some do why not save the customer some anoyance and just do it ?
I probably have heard of it more because well like i said we will do support for anyone and are open 7 days a week till late hours and the fact we have 1000 trans or more out there, I will say converter brand seems to make no difference from what I can tell and why should it? no matter who makes the converter if its a 4000 stall and the car shift to third and is not locked its going to be running 3500 rpm -+ and the PCM will expect to see 2000 or whatever cruising,

 

[QUOTE=12secSS;10893864]It really depends on the way the converter was designed. I think the STR has a big thing to do with it. Since I no longer work at B&M, I can't test this theory.

Sounds like logical reasoning.
If the pcm is set for 100% efficiancy from a stock TQ, then a STR change from a higher stalled car with a different STR of less then 100% efficiancy would cause the pcm to throw a code?
Be interesting to get a survey from people having code problems and what stall rpm w/STR vs. no code problems and what stall rpm w/STR.

Frank, i think that would be a good thread to create to answer your question, and for future reference to the board.

 

Possibly but I am not convinced its even a converter issue as far as brand etc, But I do think there are many variables that go into when it sets the code, From what I have seen it may just be under a very specific set of driving conditions, since some cars set it alot and other rarely or not at all. I think gear ratio comes into play since I have noticed from talking to people that for instance a 373 geared car seems less likely to do it than a 273 geared car.
I would imagine that as efficiency goes down such as with a high STR it would be more common,
But to me looking at EFI LIVE it simple enough just to turn it off and would cause no ill effect and would save potential though harmless strife for the customer,
Thats the real point in my question is , Why not just turn it off with any high stall and never have to worry with it? To me that makes the most sense which is why when i am ask by our customers about tuning with our trans. I say two things,
Leave the line presure stock and turn off PO757 beyond that its all up to the tuner as its not my area of expertise.
Another thing I would mention I see alot of post about concerning lockup is random lock unlock related to false engine missfire detection and IMO if i was tuning I would likely raise those table up to automatically just to make sure it didnt happen, I think what I am talking about is not so much fixing a problem after it happens but more like preventative measures , Like a vaccine against the flu, Yea theres decent odds you may never suffer it at all but why not address it before hand so theres no chance you will

 

Those are all very valid points and I agree they are more preventative measures that should be done when running large converters. Even though I run a vacuum-modulated trans now, I have never adjusted line pressure on any of my vehicles including my TB SS.

 

[QUOTE=dondb;10899391]Mine didnt throw the "limp mode" code till about 6 months and 8k miles after building the trans and throwing a 3k 2.1str stall in it. EFI Live fixed that issue for me

 

does the converter actually lock when you are in drive from the factory? i thought it only did it in overdrive but i don't know anything about it.

 

My tuner had to turn "3rd" gear lock-up off for me or "d" in camaro's i think. So I'm assuming it should lock up in 3rd stock... not sure what mph @..

 

With the factory tune it can lockup in 3rd or 4th gear ,

 

With my TCI 3000 I didn't have the problem. When I went to the Yank SS3600, it would go into limp mode every time I launched at the track. So ... it depends on the converter, and it would be wise, as you suggest, to just take care of it from the get-go when installing a hi-stall converter.

I've also had to modify my misfire codes with the Yank. Again, no issues with the TCI 3000 - all I did with that converter was adjust shift and lock-up points for driveability.

 

after i got my cam and 3200 stall tuned and everything i was driving home and the SES light popped up. my car drove like ****. bucked all over the place, died out..got the code scanned and it turns out to be the code that frank just mentioned. P0757. so i called frank @ performabuilt and he told me it just needs to be deleted. so after being all worried thinking my tranny was gonna be toast after i spent that amount of money on mods, i sent my pcm to my tuner to get it deleted. the car definitely drives a lot better..


just glad we have great sponsors like performabuilt and FLT!!

 

My SS3200 did this as well. It drove fine after the code was turned off.

 

Like I said I get alotta calls on this from people with a wide range of trans vendors and converter manufacturers which is why I posted this , Its really a suggestion that you have this done automatically with a cam install and avoid the panic lol

 

how much did your misfire tables need to be changed? i have been told to reduce it by 3-5 times the factory setting depending on the cam you have. i am not meaning to hijack frank. i felt this kind of went along with the discussion.

 

I have ran my TCI 4K for almost 4 yrs now never got this code.