2005 Silverado 4wd transmission codes 740, 758, & P2761

[Summajet]

I have an 05 Silverado crew cab 5.3L L460E transmission. I am getting codes, 740,758, & P2761.
I did a fluid/filter change two weeks ago and since that time I have been getting the codes. Fluid and filter were changed and replaced with ACDelco transmission fluid.

When I change the fluid in the filter it did not have a drain plug on the pan so I got out most of the fluid I could and the pan on the rear end of the transmission side did hang up against the transmission harness.

I have researched on the internet and came across several issues and what people posted was the fix.

1. Transmission harness

2. Ignition key

3. Pink wire running from the ignition fuse under the driver's side - to the transmission had a break in the pink wire circuit.

I cleared the codes two days ago and have driven it since with no issues. This morning when I started the truck up in the driveway to check engine light came on and it's the same as that codes as before which leads me to believe it's possible it's an ignition key issue?

I would greatly appreciate any helps or suggestions on trying to troubleshoot this issue.

Thanks

 

[Tahoe14]

Maybe Nick can help @NickTransmissions

 

[NickTransmissions]

I have an 05 Silverado crew cab 5.3L L460E transmission. I am getting codes, 740,758, & P2761.
I did a fluid/filter change two weeks ago and since that time I have been getting the codes. Fluid and filter were changed and replaced with ACDelco transmission fluid.

When I change the fluid in the filter it did not have a drain plug on the pan so I got out most of the fluid I could and the pan on the rear end of the transmission side did hang up against the transmission harness.

I have researched on the internet and came across several issues and what people posted was the fix.

1. Transmission harness

2. Ignition key

3. Pink wire running from the ignition fuse under the driver's side - to the transmission had a break in the pink wire circuit.

I cleared the codes two days ago and have driven it since with no issues. This morning when I started the truck up in the driveway to check engine light came on and it's the same as that codes as before which leads me to believe it's possible it's an ignition key issue?

I would greatly appreciate any helps or suggestions on trying to troubleshoot this issue.

Thanks

My guess is you knocked something around taking the oan off or putting it back on - it's all to easy to do as those solenoids dont need much in the way of motivation to quit on you...

Drop the pan and stick a multimeter to all of your solenoids then check for voltage at vehicle wiring harness that connects to the transmisson. The ATSG manual will have the wiring diagrams. If you dont have the manual let me know and ill post screenshots of the relevant content here.

 

[Summajet]

I appreciate the reply. I did pull a wiring harness today just in case my current one is bad. clCan you post the images for reference.
Thanks

 

[NickTransmissions]

I appreciate the reply. I did pull a wiring harness today just in case my current one is bad. clCan you post the images for reference.
Thanks

Ill post them in the AM...when you say you "pulled a wiring harness", what does that mean?

 

[Summajet]

Sorry, I pulled a used wiring harness from an 06 Silverado L460E at my local junk yard. I also was able to order a new harness made by Atp though Advance Auto just in case. At the junk yard I also saw a connecting harness that locks in place on the outer top of the transmission. It has two tabs that you push allowing the harness to separate. It provides me with feeling for the tabs as I am unable to see it while in the truck.
Thanks

 

[NickTransmissions]

Sorry, I pulled a used wiring harness from an 06 Silverado L460E at my local junk yard. I also was able to order a new harness made by Atp though Advance Auto just in case. At the junk yard I also saw a connecting harness that locks in place on the outer top of the transmission. It has two tabs that you push allowing the harness to separate. It provides me with feeling for the tabs as I am unable to see it while in the truck.
Thanks

Id buy a brand new harness but it's up to you as used ones have generally a poor track record...

Here's those images, sorry for the delay - it's been a busy day...

 

[rockola1971]

The solenoids just dont fail commonly. But the problem lies in the wiring harness within the tranny. It is constantly bathed in very hot tranny fluid and is cold/hot cycled. The wires and their insulation can get brittle. You may have caused a break in a wire and it just isnt worth the hassle to put a used harness in there. The wire (copper part) can be broken and the outer insulation can be fine. A simple ohmeter check can be made on the harness but id just yank it out and install a new one since yours is probably already baked to death from the tranny fluid heat. Check the old one on the bench to find the exact fault. While you are in there verify the filter is fully engaged into the valve body and make sure you have the correct filter installed. (Deep pan or shallow pan)

 

[NickTransmissions]

I never ever reuse transmission wiring harnesses - they all go in the trash and new ones installed on reassbly. Hopefully, he got the junkard one for free or at most a few dollars...

 

[Summajet]

I appreciate the information. It is a deep pan and I installed the ac delco filter for deep pan. I am waiting till the new harness arrives before removing the pan. I agree only to use the new harness as any old harness will develop issues over time for bathing in hot fluid.