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Just got the code P0740 (no CEL) in my 99 996 Tip. Would description be the same as the Boxter, torque converter clutch issue?

The car seems to run perfect, and the transmission is smooth as silk. I am a bit perplexed and heading. Thank you


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Had to wait 4 hours for oil to cool down to 35C. Added with the pump about a quart of ATF before it began to spill, I was surprised. The older ATF looks pretty dirty, so will do a full drain and refill this weekend. Hope that is it and not a major mechanical issue. Will keep checking the codes and let you know. Thank you


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I don't own, and therefore am not as familiar with, the Tip transmission, but in my past ownership experience of automatic cars, a simple drain and fill was not every effective at replacing the fluid. In particular this does not change the fluid residing in the torque converter itself. I believe a drain and fill generally changes about 20% of the actual fluid in the system. Many people prefer a full flush which actually drains and fills the system while it's running and pumping to do a full change. Alternatively you can repeat the drain and fill procedure without it running multiple times to bring the old fluid to a dilution level you're comfortable with.


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13K miles ago I did the filter, gasket and fluid. So I probably won't change filter again. Hopefully it was just low on fluid, but will track the code for the next few hundred miles. After adding more fluid last night, it doesn't "feel" to shift any different, still smooth as silk. Thanks


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This morning drained and fillled (almost 6 quarts out of the 9 needed for full capacity) of ATF. Follwed shop manual instructions of drain and filled. The old one, with only 13K miles, was pretty black. I am wondering if 10 track days (200-250 miles each) since last change puts more strain on the Tip. Codes are cleared, so will check daily to see if it recurs.

The shifting was very smooth still, no issues on power, all else was perfect with the Tip even on a 100F day on track.

Fluid was at 38C when changed, and a quick drive afterwards showed no difference in shifting, as measured by the "butt meter"

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  • 3 months later...

Here is the fix for code 0740 on Tiptronic. After refilling fluid (by the dealer the last time), the code would come back after 100 miles or so. The potential fix from Porsche was a new tansmission, around $7K. Before I spend that kind of money, did some research that lead me to the following for P0740 code:


Since the fluid was changed, went to step 3. Here is the location of the pressure regulator and how to remove it. You have to drain the fluid and remove the ATF pan to get to this part, then it will be obvious. There are ATF filter change instuctions in the DIY that will help with additional detail.



Part number is 986 352 603 00

I know, it is a Boxter part, but that is the part listed for the 996 too. $220 or so in my hands, easy install. The only difference I did notice post install was how much quicker the transmission will shift upwards. For example, 5th gear could come at 38mph, before the fix it was 48-50mph. Short of that, same smooth shifting. And a heck of a lot cheaper than a new tranny.

Hope this saves others some $$ :drive:


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  • 5 years later...

Thanks for the awesome info, I would have been lost without your post.

If anyone else is trying to look for the Pressure Regulator I found it under part # 986 325 603 00

The best I could find was for $320, where did you see it for $220?

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  • 8 years later...

I ran across this post. What timing. Hope some one is still on it. Been dealing with the 0740 torque converter lock up code.  Since I am in Ca. It will not pass smog. Car runs great. It’s an O1 986 S. Have had it almost 20 years. I too love this car. I think I found the part number  for the solenoid but not sure.  986 325 601 00. Getting up there  in years so the getting at is getting tougher, but doable. Would appreciate any help given. I see from this post the part number I have was incorrect,  but which one is it? ABCDEF or G?

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This is a 10+ year old post so part numbers listed may very likely have been superseded.  I would call Sunset, give them your VIN, and order the latest part from them.


This is a fantastic thread.....the information given by Izzy is very helpful.

Edited by Silver_TT
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  • 9 months later...

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