Noone

Hi!
Please help. Does anybody know why the the ECM provides 3 cables to lockup the Transmission?
We rebuild another Transmission and i have only 2 Inputs on the Transmission. One Ground that goes to a pressure Switch and than to the Solenoid and the
12V + coming from the brake Switch. So for what is the 3rd cable?
thanks alot
Martin

RBob

iTrader: (1)

The third wire is typically a pressure switch on the 4th (OD) circuit. Lets the ECM know when the trans is in 4th. Mostly uses that signal to use a different setup of TCC lockup tables. Versus the 2nd and 3rd gear tables.

RBob.

Noone

Thank you. Can i atach it to a ground? I do not want to change the setup in the transmission. Thanks

RBob

iTrader: (1)

No need to connect the 3rd wire to anything. Sounds like the way it is wired is that it auto-locks once in 4th gear. This is common when lockup is desired on the highway and the ECM is no longer in place.

RBob.

Noone

Hi. The ecm is still in place. My problem is that i only have 2 contacts on the tranny but 3 wires from the ecm.
martin

RBob

iTrader: (1)

Right, don't do anything but plug the connector into the trans.

RBob.

Noone

Yes. But my trans don't tell the ecm that i am in the 4th gear. So i beleive i have no tcc lockup.

RBob

iTrader: (1)

I need a picture of the wiring under the pan.

RBob.

Noone

Hi!
I have no Picture. The Transmission is on the car and filled with oil.
The rebuilder told me so: Pin A Goes the + to the tcc Solenoid. Pin B Goes Ground to the Two pin 4th Gear Switch and from this Switch to the Ground from the Solenoid.
So if the Trans is in 4Gear the Switch connects the ground coming from the ECM to the Solenoid.
What i do not know is what the 3rd cable is on the harness. If it is a 4th gear indicator for the ecm can i put ground to it?
Hope you know what i mean.
thanks
Martin