2004-2005 LLY OS is the only TCM OS that has decent/aggressive grade braking. 2001-2002 has worthless grade braking. 2003 and 2006+ its "ok", but not anywhere near as aggressive as 04-05.
5 speed tcm OS's
- Thread starter mike diesel
- Start date
2004-2005 LLY OS is the only TCM OS that has decent/aggressive grade braking. 2001-2002 has worthless grade braking. 2003 and 2006+ its "ok", but not anywhere near as aggressive as 04-05.
Ben, someone mentioned that you had a write up of all the os and pros of cons of each, can you share the link to where its at? I looked couldn't find it
15077860 is one of the oldest 2001 OS's, with no overdrive lockout enabled
15175854 was the first TCM update that GM enabled ODLO on. It is also the one that shifts awesome with big power. It does NOT have the TCC protection tables mapped.
So if '5854 has the TCC tables mapped, it would be "the one" for all 5-speeds to run. But it doesnt, go figure.
So take your pick....a TCM that shifts flawlessly all the time, or a TCM that locks the converter properly/on time
15175854 was the first TCM update that GM enabled ODLO on. It is also the one that shifts awesome with big power. It does NOT have the TCC protection tables mapped.
So if '5854 has the TCC tables mapped, it would be "the one" for all 5-speeds to run. But it doesnt, go figure.
So take your pick....a TCM that shifts flawlessly all the time, or a TCM that locks the converter properly/on time
Im trying to find it too. I posted one thing I said above...but I cant find the long in depth post I made....
Im trying to find it too. I posted one thing I said above...but I cant find the long in depth post I made....
So with all the things mentioned, there really isn't a go-to OS that has the ODLO, the better grade braking, the better lockup and shifts the better all in one package.
I'll keep using the 5854 OS that shifts flawlessly and use your lock up box to lock the converter properly
Im trying to find it too. I posted one thing I said above...but I cant find the long in depth post I made....
I remember this post..is this the one you're thinking of?
ALL of the TCM OS's except one have those D5231, D5233 tables mapped out.
2004.5+ TCM OS's also have an additional table, D5232, "TCC apply slip limit at full throttle"...Ross said that D5232 does not exist in 2001-2004 LB7 OS's.
Go figure, the one 2001 TCM OS that I love and exclusively use (15175854) is the one that doesnt have those tables mapped out yet.
There are several 2001 TCM OS's. All of the 2001 OS's except 15175854 have the tables mapped, and all 2002+ TCM OS's have the tables mapped.
Cindy (cindy meyers, at EFILive) sent me an email saying that Ross is working on it and in the next public release, 15175854 will have the TCC protection tables mapped out. So in the mean time, I just switched to another 2001 OS, 15079907, which does have the TCC protection tables mapped.
The reason that 15175854 is my favorite, is because it shifts the best, and the adapts are slowed way down so you can "sneak up on the F'er" (as Mike says
BUT...the kicker is that the 2004-2005 LLY TCM does have a huge redeeming factor that none of the other TCM OS's have. The 04-05 LLY OS does NOT release TCC under part-to-full-throttle kickdown when the TCC is locked. So with an 04-05 LLY TCM OS, when you're on the highway in 5th locked, and you stuff it to go pass someone, the TCC stays locked through the 5-4 WOT downshift and never unlocks.
2001-2004 LB7 TCM OS's, under any locked downshift above 10% throttle, the TCM unlocks TCC, performs the downshift, and then relocks TCC. Its annoying because when you go to pass someone on the highway and do a WOT 5-4 downshift, the TCC unlocks, and you're sitting there, RPM's screaming, not accelerating for a second or so before the TCM relocks TCC and you actually start getting the power to the wheels again.
The only conditions in which a 2001-2004 LB7 TCM OS will do a locked downshift is under 10% throttle when in tow/haul mode...for grade braking purposes (because that would degrade grade-braking performance to unlock TCC during a grade-braking-downshift). Like I said, its annoying and I dont know why Allison programmed it that way on 2001-2004 TCM OS's, and then decided otherwise on 04-05 TCM OS's.
So yeah...there is no "perfect" TCM that combines everything.
My perfect/ideal TCM would be:
1) The shifting and slow-learning/adapts of 15175854
2) Auto high-idle support for LLY's (if you run 15175854, auto high-idle doesnt work on LLY's, on 2002+ TCM OS's, auto high-idle works)
3) WOT TCC-locked downshift programming of 04-05 LLY OS
Oh well. I can live without auto high-idle working, but TCC release on WOT downshift is really annoying on the 01-04 OS's. At some point I would like to try to compare bins in hex and see if I can add the 04-05 TCC attributes to the earlier OS's. Because I doubt anyone else is picky enough/cares enough to look into it.......
There are some other tables, D5073, D5074, D5075 that were added in the latest EFILive version too. I havent found out what they do yet. At first I thought they might be for the above mentioned issue (unlock on WOT downshift in the 01-04 OS's....but when I compared D5073, D5074, D5075 in both 01-04 and 04.5-05 OS's, they were identical....so obviously that mystery "unlock on WOT downshift" table is hidden and isnt mapped unfortunately.
D5067, D5068, D5069 "TCC WOT release" do nothing. Ive set those all to low MPH on 01-04 OS's and it still unlocks under WOT downshift. IMO there are a lot of Allison tables in EFILive that are either mis-labeled, or dont do anything at all.........
Ben
From this thread... http://www.duramaxdiesels.com/forum/showthread.php?t=59118
Nope.
So then the 03 is probably the best all around, does it have ODLO though
Depends, OD/LO works like stock for 03-05 trucks with the 03-04 LB7 OS. If you have an 01-02, then you will never get OD/LO with it as the 99-02 BCM does not send out the OD/LO command like it does in 03-05 trucks.
I like it's grade braking myself, MUCH better than my current 01's.
I haven't tried an 04-05 LLY OS, but I know when I ran the 02, it would go into grade braking at the drop of a pin. If I even looked at the brake pedal wrong, it would kick down even in regular mode. I know others have tried it, and had the same results. This was the later 03/02+ build date 02 trans OS, never tried the 1st 02 OS(the one without OD/LO via the external hard wired momentary switch). But I will admit the 01's grade braking SUCKS! It always waits until after you are down hard on the binders for WAY to long to kick in. Never towed with the 03-04 LB7 OS to see how it did in the mountains.
What are you talking about? Yes the 01 has slow adapts, but they CAN be reset. The 01 OS cannot do the fast learn via a TECH 2 like 02+ OS's can, but that is it. You can go in and reset them all, or each one individually. And I have never had problems with it taking to long to relearn. If you reset them back to fast correctly, they learn the base shifts just as fast or faster than other OS's do.
Just my $.02 as I have tried most all of these OS's, and my own personnal opinions of them. I wish I could get the shifts of the 01, with the grade braking of the 02, retain the hard wired OD/LO like 01-02 use, but have it stay locked in lower like 04-05 LLY's do. I guess I need to add in a G solenoid or simulator to mine so I can try out an LLY OS, and see how it shifts. I tried it once before, and it pissed mine off ROYALLY(wouldn't even move, went straight to limp mode with no gears. I think it's due to mine being a swap).