Codes P0740, p0753, p0785, p1860?

Here is information on the codes:

P0740: Torque Converter Clutch Circuit Malfunction.

P0753: Shift Solenoid A Electrical Malfunction.

P0785: Shift/Timing Solenoid Malfunction.

P1860: TCC PWM Solenoid Circuit Electrical Malfunction.

I would start by checking the electrical connector at the transmission. If that looks okay, I would install a rebuilt valve body. Check out the images (below). Please let us know what happens. Also, how is the fluid condition, is it burnt or low?

The fluid is good. I dropped the pain and checked the shift solenoids, and they were good. I cleaned everything while I was there. Changed the filter and put new fluid in. Do you think putting a new harness in would fix my problem? i have done a little research and it seems that that could possibly fix it.

Yes, if the wiring is bad, it will cause this problem. Here is a guide to help you test the wiring with the transmission wiring diagrams below:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Please let us know what happens.

The valves in the valve body moved easily. So, I don't think it's that. That why I asked about harness. Thank you for the info. I will let you know how it goes.

The valves in the valve body moved easily. So I don't think it's that. That why I asked about harness. Thank you for the info. I will let you know how it goes

Please do, have a great day.

i replaced the harness in the transmission. the truck can move better. i don't have to almost floor it to move. but the codes are still there after clearing them with the scanner. also still can't feel or hear the truck shift. What would the next step be?

I would install a rebuilt valve body, or you could have a bad PCM. How is the fluid condition?

This guide can help:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Please go over this guide and get back to us.

Can a bad ignition switch cause these shifting problems? My tachometer and speedometer on my cluster stopped working. And then all these problems started.

Yes, it could, here is how to change the switch out in the images below. Check out the images (below). Please let us know what happens.

Ignition switch did not .

It seems like it is the valve body or the wiring, did all of these codes come in only after you changed the transmission out?

Okay. So, I bought this truck. The motor was locked up. It blew the cylinder walls out. So, I put a new motor in. The transmission was rebuilt about two years ago. It was all running good for about two weeks then all of the codes appeared. I have changed the internal harness. All new solenoids, new filter. And ignition switch. The only thing I haven't changed is the valve body and pump.

I'm also going to check my converter make sure it's not loose.

Any way you could send me all wiring diagrams for my transmission?

They are in the post above, click to enlarge in the images.

could the gauge cluster not working cause my no shift issue?

So, the speedometer is not working? If so, this can be the problem, I would swap out the VSS sensor. Check out the images (below). Please let us know how it goes.

I know this is an old post but did you ever find a solution? I have a 02 Escalade with the exact symptoms.

Good question, I just spoke with EARL91 so he should respond. I think the transmission needed to be rebuilt.

The gauge cluster being replaced did fix my issue.

So the cluster caused those codes? Thanks for letting us know.