NEED HELP 05 avalanche transmission codes n issues

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
I've got an 05 chevy avalanche 1500 she has given codes p0740 p0753 p0758 p2761 she will not get up and go when on the slightest incline I've already replaced ignition switch and serviced the transmission is their a fuse I'm missing or is it the torque converter clutch solenoid any and all help is greatly appreciated
 

Sparky

Member
Dec 4, 2011
12,927
I don't know the exact fuse numbering but I'd be checking all of them. After that, check the wiring harness connection to the transmission at least as a first step.

Given those codes are for multiple different circuits in the transmission I'd suspect not a simple solenoid issue but some wiring issue of some sort.

For reference:

P0740 Torque Converter Clutch Circuit Malfunction
P0753 Shift Solenoid A Electrical
p0758 Shift Solenoid B Electrical
P2761 Torque Converter Clutch Pressure Control Solenoid Control Circuit/Open
 

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
checked wiring harness n all is their another fuse box I don't know of checked one under hood n in cab all looked good
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
That should be it for fuse boxes. Did you check the ground wire for the transmission harness? I could just that wire killing everything. Try to find a copy of the wiring schematic. Unfortunately the ones in my signature link are for GMT360/370 only.
 

Tiggerr

Member
Jun 6, 2013
1,324
Perrysburg, OH
Sounds like that whole harness to the valve body is out....definitely check grounds and all connections/wires....
Doesn't sound like a mechanical problem, with the trans
 

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
I've checked all connections and fuses still is kicking same codes also cleared codes on computer they're still coming back up would a piece of trash in trans. cause it or is there a bad sensor causing the torque converter clutch pressure control solenoid circuit to stay open

I've also changed the filter on transmission as well

I want to thank you guys before I forget everything that you've said has helped very much I may have her figured out but still post any ideas and help you can offer once I get it fixed Ill post it for everyone to see.

MOD EDIT: Please refrain from posting multiple times consecutively. If you need to add more, please use the edit button. Thanks.
 
Last edited by a moderator:

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
What codes are you getting now? Please be specific.
 

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
still getting same codes as before p0740 p0753 p0758 p2761 planning on taking it to shop this coming week if I cant figure it out would it possibly be the speed sensors I'm shooting in the dark now
 

budwich

Member
Jun 16, 2013
2,027
kanata
I hope you used a meter to check your fuse position and didn't just use your eyes... right?

further which fuse was it that you checked with that meter?.... :smile:

like most things GM and like the youtube video, there are "jumper links" in the system.... :smile: So if you had voltage at the fuse, then then next place is likely the jumper.
 
Last edited:
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Do report back what you find out from the shop and what the repair was. Definitely interested in this.
 
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budwich

Member
Jun 16, 2013
2,027
kanata
hopefully if it goes to a shop, they are "nice" cause it is more than likely a "simple" powering / cable issue.
 

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
dropped it off this afternoon good shop my mother uses them when I don't have the right tools, don't have time or its way too involved for me to handle in my yard
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Please do report back what they find. it would be good for the next one with the same problem.
 
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kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
Shop is saying its the transmission itself won't tell me what part it is in transmission also saying that it doesn't matter what part its just the transmission I'm I wrong to think that they might be shooting me a line to make a good payday also would a bad torque converter solenoid switch cause the same issue cause p2761 torque clutch solenoid circuit is open
 

Tiggerr

Member
Jun 6, 2013
1,324
Perrysburg, OH
Shop is saying its the transmission itself won't tell me what part it is in transmission also saying that it doesn't matter what part its just the transmission I'm I wrong to think that they might be shooting me a line to make a good payday also would a bad torque converter solenoid switch cause the same issue cause p2761 torque clutch solenoid circuit is open

I'd definitely get a 2nd opinion!

I'm no trans expert but what you've described sounds electrical to me..
not like a physical/mechanical issue internally..IMHO
 

budwich

Member
Jun 16, 2013
2,027
kanata
As suggested, you need to follow the suggestions (get a meter and check things / answer the questions from people who are trying to help) or "pay the piper and hold your breath".

It is not likely to a be solenoid issue causing multiple codes across different components. Its more of a wiring / connection / fuse problem. It will be a BIGGER problem if you keep driving it the way it is.
 
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Capote

Supporting Donor
Member
Jul 14, 2014
24,227
Atlanta, GA
They're trying to get money out of you for sure and probably didn't fully try to even diagnose the issue in full. Definitely aims towards an electrical/wiring issue like everyone has been figuring. Highly unlikely all those issues would occur at once.
 

kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
have a friend at a transmission shop here in town said same thing they everyone else on here is saying within two minutes after talking to guy there he said it was stuck in 3rd and that it was a small electrical issue they would know by monday afternoon what was up and they would call me You all have been a very big help I'll post results as soon as I get them
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Definitely interested in the results.

Glad we were able to help. If you feel like it, could you donate to the
The Tip Jar? Even a dollar or two would help keep this site and it's information online.
 
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kaiju

Original poster
Member
Apr 27, 2017
9
jackson Ga.
Got truck back today the shift solenoid needed replacing and somehow fluid got into the wire harness so he replaced both solenoids and harness also redid the other electronics on valve body come to find out the first shop had broke the plastic piece on shift cable so I had him put new one on as well total cost 500$ even I want to thank you guys again for all your help You certainly live up to your reputation as the top place to go for gm trucks
 

Sparky

Member
Dec 4, 2011
12,927
Sorry to hear it still cost that much, but at least it cost a lot less than a whole transmission!
 

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