plummr

Does anyone know which wire you energize and/or ground in order to get a 4l60e tranny to shift into first?

I've got 2nd and 3rd by default with tranny un-plugged, due to it being in a 91 chevy, but what the heck it was free. I'm aware of the Trans-Go kit's, thank's to you guys, but If I could throw a few volts down one of the harness leads to get first gear I'd be in pretty good shape. I only need it for a few weeks, but I'm getting concerned about these 2nd gear starts. Not to fun to drive either.

Thank's

4L60bliss

Actually, your getting 3rd by default, and your forcing 2nd by putting it in the manual 2nd position. It will start in 2nd wether its working properly or in default as long as you put it in manual 2nd.

Anyhow, to get first gear, BOTH shift soleniods (1-2 and 2-3 shift solenoids) have to be energized.


Here is the top view of the connector. You need to supply power to the solenoids via pin E and then ground the 1-2 shift solenoid via pin A and the 2-3 shift solenoid via pin B.

plummr

Thank you so much.

I assume were talking 12 volts correct?
and does it matter if I have a constant positive to Pin E and put the switch on the ground pins? or vice versa?

Thank's again

4L60bliss

Yes, we are dealing w/ 12 Volts. The 4L60-E is wired to recieve ignition voltage on Pin E to power the solenoids. Then, as shifting is needed, the PCM grounds the solenoids, so how you planned on doing it is correct.
When the 4L60-E first came out, Kent-Moore sent us a box w/ a dial to shift the tranny and buttons for TCC enable and such for use in diagnosing these trannies, but since then, we have been using the Tech2 (GM Scantool) to do the shifting for us for difficult diagnostics. If this tranny was a long term thing, maybe you could build a box similar to the Kent-Moore and manual shift the tranny w/ from a box on the front seat

Also notice that there is a 3-2 downshift solenoid, and two TCC solenoids on this tranny, as well as an electronic Pressure Control Solenoid That will be disabled. With the Pressure control solenoid disconected, it defaults to MAX pressure. Nor will you have TCC lockup.

plummr

Hmmm, now u got me think'n.

It would'nt be that much more difficult to put a 5 way dial type switch in. I might get ambitious and make up the box. If so which leads ground for 2nd,3rd and 4th? Also would reverse and neutral still be manually shifted only or do they have grounded soleniod's for the shifts?

Thank's again,

If your a transmission man. U just picked up a customer for life.
This being a poor boy is about to end.

4L60bliss

Getting the shift solenoids to work won't be a problem. Getting the TCC and 3-2 downshift to function properly will be the trick. Depending on what year the tranny is, the TCC used a PWM (Pulse width modulated) solenoid to gradually increase apply fluid to the TCC solenoid.

Reverse and Nuetral don't use solenoids and won't require use of the solenoids, however during Park, Reverse and Nuetral, the PCM keeps them energized (even though they aren't used) in anticipation of a change into first gear.

plummr

Yeah, I didn't think it would be that easy. Oh well maybe I'll just stick with plan A.

Thank's Again.

Danno

If you try to run it without a controller or PCM it will NEVER work right and running it at full line pressure will ultimately destroy it.

4L60bliss

Yeah, I think he figured that, this was just a temporary solution. If I remember correctly, he was going to put a T56? in, in about a month.

Edit: I went back and looked at the original post, he is giving the truck away to charity in a month...

paveuk

Ok guys i'd appreciate some help too, this one is for my 98 chevy truck. I don't have first or fourth. I verified 12 volts to the solenoids, and grounded them out and heard clicks. So there is voltage, and the shift solenoids work. What would it be next, my ecm isn't grounding them out? But if you need both ss a and b energized which they are, shouldn't it be in first already? I troublshot as far as I can, and short of replacing the ecm i'm lost.