Twin_Turbo

iTrader: (25)

My tcc wont lock up. The system is running open loop for now. Even after lowering enable temp. Is closed loop required for tcc lockup? I thought it was just speed temp and pressure switch.

htrdbmr

Mine has to be in closed loop.

RBob

iTrader: (1)

I don't know of any ECMs/Masks that required closed loop for TCC lockup. Is the ECM not commanding lockup?

Which mask are you working with?

RBob.

htrdbmr

Stock mask. I'm new at this, I think I'll just sit back and listen for a month or so.

RBob

iTrader: (1)

OK, stock mask for what vehicle and drive train?

RBob.

RBob

iTrader: (1)

Was wondering which ECM/mask you are using. With that I can possibly take a look at the ECM firmware.

RBob.

htrdbmr

Vehicle is '92 BMW 735, small block 383 w/ Mini Ram, 700R4, -727 ecm from '91 vette.

RBob

iTrader: (1)

Looked through the $8D mask firmware and show nothing that would cause the TCC not to lock when the ECM is in open loop. So... slapped a '7730 on the bench and blew in the ANHT BIN ('90 Corvette auto).

TCC locks up before the ECM goes into closed loop.

Blew in AUJP ('90 - '92 Camaro/Firebird) and the same thing. TCC would lock up before the ECM goes into closed loop.

Edited an ANHT BIN by setting the closed loop enable temperature high. ECM never goes into closed loop and the TCC works as it should.

RBob.

Twin_Turbo

iTrader: (25)

Ok thanks. That was my suspicion as well...now congirmed. Now to find out why the damned thing wont work. My red brick scanner only shows p1 or p2 whatever that is. P-N. and -R-D321 indicate correctly. The brake pedal switxh works and I have 12v. Also the press switch setting in bin is correct.

Twin_Turbo

iTrader: (25)

Well, it's still not working. I hooked the scanner up, 4th gear switch status changes just fine (p1 in 1-3 P2 in 4th), speed signal works w/ 8K pulse and vehicle speed in stream reads correctly. Still commanded lockup remains in P1, it will not lock up. I think it might require closed loop afterall. Using $8d on a 1227727 weatherpack ECU. Brake switch operates fine. The ECU simply does not command lockup,.

Twin_Turbo

iTrader: (25)

TCCR=TCC Control On=RPM

If I set this to on I assume TCC is controlled based on rpm instead of road speed. Where does one find the rpm setting for this?

RBob

iTrader: (1)

It uses the same lock/unlock TPS vs MPH tables. It is just that the tables are RPM based instead of MPH based.

I was wondering which BCC you started with. Looking at AXCN, a 6-spd y-body BIN, doesn't have most of the TCC parameters/tables populated.

With this flag having to be cleared:

RBob.

Twin_Turbo

iTrader: (25)

I got it to work by setting the unlock prevention to 45mph just to test and sure enough it commands P2 and locks up just fine. I'm going to set this to 255 because it's bloody annoying that it won't release and you loose TQ multiplication. So...something is keeping the routine from locking (or better yet, telling it to unlock the TCC) gotta figure out what, I started w/ a 92 GTA bin, it has the proper 4th gear switch NO setting, the vette has it reversed. I took the TCC tables from the vette however.

Twin_Turbo

iTrader: (25)

could it be a problem with super $8d? I see no switch for tcc or shift light. Maybe it's somehow set to shift light making the tcc inoperable. I have no idea where that switch resides.

Twin_Turbo

iTrader: (25)

Well...got it working YAY!! Turns out the prom that came in the system was some kind of hacked up manual prom set to work on an auto and possibly without tcc. One of the undefined bits must have been the issue. Started with a 91 vette a4 2.73axle prom since that matches the peg leg granny rear in my truck (wouldn't want it shroter, the damned thing is twitchy as hell as it is and blasting the autobahn at over 140mph sure is fun.. people staring because of a lame old truck passing them at speed LOL)

Now to tweak the lockup a bit so it disengages with less throttle..right now it tranitions violently because it's set around 25% throttle, which in my case is tire spinning levels

Thanks especially to you rbob

Drawmain

I'm having a similar problem since I swapped to a 3:54 rear. TCC lockup is no longer working. Just started researching today, hopefully I'll find the issue. EBL still has the same tune as it had when running the 2.87 rear. Any help as always is appreciated, TCC locked fine before the swap, all we did in the trans was install the correct gear to drive the speedo and did a trans fluid and filter change while we were in there. Old fluid was fine, still red, didn't smell burnt, not discolored, no unwanted metal or trash in the fluid.

RBob

iTrader: (1)

Probably knocked the wires or connector loose at the trans. Try this, key-on, engine-off and measure the voltage on pin F of the ALDL connector.

Should be +12 volts. If so then ground pin F and listen for the TCC solenoid to click. If it does then the ECM should also cause it to lock up.

Note: not knowing which actual vehicle and MY it is, ALDL pin F may or may not be the TCC lock signal from the ECM.

RBob.

Drawmain

Its a 1982 Corvette. Drove it today and will try your test later tonight. Thanks