[sgvsafari]

So I just swapped my bad 05 AWD trans with a used low mileage one and I'm getting codes : P0740, P0785, P1810, P2761. The fluid and filter are new.
Currently when I step on the gas the car feels heavy, like you really got to give it a little extra gas to get it moving. But once you get going it runs great. All the gears shift super smooth. So I don't the trans is bad, feels like I'm overlooking something, I have double checked the plugs to make sure I didn't miss anything. Any advice or insight would be appreciated.

 

[gwd]

Sounds like you have a problem with the torque converter or the the items that control it.

 

[sgvsafari]

Sounds like you have a problem with the torque converter or the the items that control it.

I did notice that the Torque converter on the new transmission was much larger than the original one. I figure it was an upgrade.

 

[Birdshake]

Was the used low mileage one also an '05?

 

[sgvsafari]

Was the used low mileage one also an '05?

Yes. I also matched the number of pins on the harness to the plug. I believe pre 05 had 12, and 05 has 13.

 

[markmitch]

You may have to reset the ecm and let it relearn.

 

[Bikley]

I did notice that the Torque converter on the new transmission was much larger than the original one. I figure it was an upgrade.

It's probably for a V8, and if that's the case it wont ever perform right behind your V6.

 

[AstroWill]

P2761 PCM detects a continuous open, short to ground or short to voltage in the TCC PWM solenoid valve circuit
P0785 PCM detects a continuous open, short to ground or short to voltage in the 3-2 SS valve circuit
P0740 PCM detects a continuous open, short to ground or short to voltage in the TCC solenoid valve circuit
P1810 PCM detects an invalid TFP manual valve position switch state for 60 seconds.


Electrical, electrical, electrical, find/fix the others first as that might take care of the last. Get the manuals, I highly recommend the GM Techline eSI, found online esp given the prices of the manuals for the later year vans.