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Discussion Starter #1
Hello, getting codes P0700 along with P0741. Car is 07 Cobalt LT coupe. 2.2 Auto.

The car runs great. If I erase the code and just drive around town it won't come back on. It will come on once I get on the freeway, and even then the car still feels good at 75 mph, no hiccups or anything.

Could it be the Torque converter clutch solenoid?

Can someone post a DIY thread on how to replace it or how to fix this?

Thanks,
 

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I would first verify fluid levels at full operating temperature. The torque converter will have a hard time keeping lock up if oil is low because oil pressure drops. TC could also be limited by dirty oil, you could add a bit of transmission fix fluid to increase torque converter pressure.

Circuit Description
The torque converter clutch (TCC) solenoid valve is a pulse width modulation (PWM) solenoid. When vehicle operating conditions are appropriate for TCC application, the transmission control module (TCM) begins the TCC duty cycle at approximately 42 percent. The TCM then increases the duty cycle up to 90 percent, in order to achieve full TCC apply pressure.

When the TCC PWM solenoid valve is de-energized, the solenoid blocks filtered 2-3 drive fluid, and allows TCC signal fluid to exhaust. When energized, the solenoid modulates fluid into the TCC signal fluid circuit. When fully energized, modulation stops, and the solenoid blocks both 2-3 drive fluid and TCC signal fluid exhaust.

When the TCM detects a high TCC slip speed when the TCC is commanded ON, then DTC P0741 sets. DTC P0741 is a type B DTC.
 

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I had checked it and the trans fluid did seem full, but the little bit that dripped out, was dirty brownish colour. From what I had read it is supposed to be like a redish colour right?

So was thinking of changing it and the filter, so figured might as well change the torque converter clutch solenoid at the same time since its not that expensive. But don't exactly know where it is at XD can you post where it goes?

Thanks,
 

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You have to remove the side cover.

 

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Awesome, Thanks!

Haven't done anything yet but can you please post that too?

That way it will go a lot better when get into it. Will already know what to look for and how to do it.
 

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Start by changing old fluid and filter, maybe that will loosen up the TTC solenoid and you won't need to go any further. You can still add half a bottle of "Lucas" transmission fix to help clean and swell some of the seals. It won't hurt anything, I always add some to my transmission after 60000 miles. I've owned 19 GMs and I've never had a transmission problem ever. My Mitsubishi has 418600 Kms and it's still going. Preventative maintenance speaks for itself.
 

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Discussion Starter #7
Dropped the pan last night to change the fluid and filter. Erased the code. Tested it out, drove around town, and got on the freeway, doing 75 mph and no check engine light! Going through the gears and while driving, it does feel like it is shifting a lot smoother now.

Did not add any of the lucas that you were talking about, will have to see if I can find some to add.

Thinking I might do it again in a few weeks, maybe, so that the rest of the old fluid that was still in there will mix with the new, and then when I drain and add more again, it will have a lot more new fluid then old left over.
 

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Better left in capable hands of people that do it all the time, but if you want to try it it's possible and just needs patience. Have you tried the Lucas transmission fix or similar additives? This stuff dilutes in the oil so you don't have to worry about overfilling. Like when you add a litre of alcohol to a litre of water and only get 1.5 litres total.
 

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Discussion Starter #10
Can you please post the repair manuel so can change it out, thanks, or just the pages needed that cover it to do the work, been looking online but cant find anything.

Thanks,
 

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You should have PMed me because I did not see your question. This site is not equiped to upload large files like .pdf, I will try and convert the files to PNG and post them may take a while.

---------- Post added at 10:18 AM ---------- Previous post was at 10:05 AM ----------

I can't find the right procedure for your car, sorry.
 

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These are year sensitive even VIN sensative.
 
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