Jays_SSZ28

iTrader: (2)

I built a 2006 4L80E, just because I like to built them.
Mostly stock but with durability upgrades, used the existing electronics.

Well I ended up selling it to a guy at work. He has a 2005 silverado that had some weird shifting symptoms. But it would shift through all gears.
Now with my trans it only has 2nd and reverse.

I tested a few things.

I connected HP Tuners and nothing happened when commanding a shift or tcc lock up.
It sets the DTC codes for open circuit for solenoid A, B, and TCC.

Shift position PID coincides with the shifter (the PSM is working)

I checked the resistance of the shift solenoid terminals AT the case connector, all are normal (22 ohms).

I unplugged it and grounded terminals A, B, and S. Connected 12 volts to pin E. With the wheels off the ground it shifted 1st, 2nd, and lock up. I was using alligator clips and not sure if I had it on B or not.

I think it's the chassis wiring and recommended ohming the wires from the PCM to the trans case connector.

Could it be anything else?

JoeNova

Are you using the stock ECU/wiring? Is the harness set up for an 80e or is it a 60e harness?

Jays_SSZ28

iTrader: (2)

It's a factory stock truck.

JoeNova

The trans gets power from the fuse panel and the PCM provides the grounds.

Since everything is faulted out, its either not getting power from the fuse panel, or one of the grounds going from the PCM to the frame/body isn't getting good connection.

If only the trans is having problems, its probably the power from the fuse panel that's not working.

Jays_SSZ28

iTrader: (2)

going off of the transgo database troubleshooting it has you apply 12 volts to pin e and ground pins a and b and s that way it should manually shift through all the gears and have torque converter lockup that's what I did and everything worked as it should so that verifies that there is no problem with the transmission. This is all done with the trans unplugged.

Half-Fast

not sure if it helps, I see Silverado's with bad ground wires all the time on the pass side down behind the intake. I believe there are two grounds there that go bad.

forcd ind

iTrader: (7)

2nd and rev is what it faults to if no power-ck for +12 at the conn.

Jays_SSZ28

iTrader: (2)

I only built the transmission for myself, then found out he needed one so I brought it to work and he took it home.
This guy is pretty good with vehicles, but like most people, doesn't get into transmissions much.

He called me at 8pm and I went to check it with hardly none of the proper tools.

I just wanted to verify my build, and leave him with some direction on where to look next, I made this post to possibly get more ideas.

He got back to me this morning, the problem was the ignition switch. The transmission shifts fine now. Probably what was wrong with the old trans. I'm going to take it apart when I get it and see.

Thanks. PROBLEM SOLVED.