Thread: trans help!

Yea, it's the original pcm that cam with the car. I've tried checking the code with DHP but nothing shows...says "no codes found". Never tried a scan tool before. I figured it's probably a flashing glitch since it never caused a issue that I've seen...could be a bcm or bus controller code i guess. But after clear the code it never shows again till I reflash again.

I am by no means a transmission expert, but its just a question/suggestion. Have you tried disconnecting the battery for a while to reset everything? To see if that would make any difference. If already have and mentioned so, forgive me for repeating.

I dunno, it isnt my area of expertise so its just a thought.

Ok, after some trial and error messing with the trans. tables, I think I found what was causing my converter issues...kinda. Well, first off, I did get the mph and rpm tables in perf. mode fixed so they were not overlapping the TCC release/apply tables so thats ok now (was off in 3rd and 4th a good amount 1st and 2nd was ok). Raised my converter lockup settings in tourqe management, that helped so.

The biggest thing that made the difference is the trans. pressure tables. Ended up raising the 1-2, 2-3 and 3-4 pressure tables in perf. mode from 15-20% over stock to 50% to 1000% over stock. For example, so you know where my #'s are coming from check the file attachment at the bottom \/


I'm not really understanding why I had to raise them that much to begin with or even raise them at all to affect the tourqe converter lockup....but it did stop my surging problem and it lockups alot tighter then before.

Now here's the second issue thats gotta be related to the converter I'm guessing. When I drive normal when the car is warming up the trans shifts very firm and nice. After about 10-15 min. it starts to soften up on me and the shift times get longer. But sometimes it will shift firmly out of the blue. Next thing is the WOT shifts, first WOT run the car shifts 1-2 and chirps the front tires and shift firmly throughout the run. Next WOT run right after , the pressures seem to soften up and the car shifts firm but not as much. Then the third time I go WOT, the trans almost feels sloppy at the 1-2 shift

Trannyman...whats your thoughts???? I'm thinking it's a overall pressure drop issue causing my issue's and me raising pressure drastically is just covering it up.

The shifts will be a bit firmer when cold but its not going to be a big difference. If its enough difference that you feel a noticable change then I still think you have some internal pressure issues. What are the pcs amps doing when it shifts firm and then once it warms up? Again withought watching a scanner and or pressure gauge it is hard to say. There is a table in the pcm for pressure VS trans temp and if that table is not stock then it is wrong and will cause problems.

Yea, their is definitely a difference between cold and hot. Well I'll check to see if theirs the parameter in the DHP tuner that will allow me to watch the pcs voltage....other then that, DHP doesn't have "pressure VS trans temp" mapped out so I can't change or see that parameter

I did run a scan and did find out that my trans. is running @125-130* with the outside temp. at 35* after a hour of driving stopand go. Could this be part of the issue?

125-130 is pretty cold especially after an hours drive. They are normally up to the 160-180 mark after roughly 30 minutes of driving but regardless your trans isnt getting that hot so you shouldnt be seeing that much change from cold to hot as you arent really getting hot.

well I'm thinking that explains my slow lockup and my extended delay to lockup when the cars warming up. Dosent the cluches slip more when the fliud is xold like that?

The clutches wont slip more when cold and it should feel firmer being that cold since the fluid isnt so thinned out and also back to the table about trans temp vs line pressure. That will definately explain your long tcc wait time though.

Thats good to know about the cluches not being affected...I'm going to run a scan tonight to see if everything else is ok with the TPS, duty cycle, etc. Thanks again trannyman

Well trannyman /guys, the problems fixed. Would you believe the timing tables were the culprit? With the addition of the larger TB, the 97.5 tables are so low on timing overall. Flashed the pcm with 99 tables and almost 100%, then just tweaked a few more mph tables and all good! Thanks for your time and effort everyone

That is great news. Glad you got it all figured out. This needs to be stickied or something as this was quite the unusual thing.

Good find! Glad you found a fix and that it helped out. A larger throttle body will also slow down the airflow across the maf sensor and this will lower trans pressures, especially at WOT, so that may be something else to keep an eye on if it gives you any more fits down the road though after a proper tune you should be fine in this area.

yep, ready for the track now. Seeing a blimp of kr in 4th going up hills but 0 kr at WOT, 900-910 o2's..lol (I know, lean)