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Discussion Starter #1
So, over the last few months, the car has gone from occasionally throwing these codes (1-2 times every few months, when very cold) to being almost permanently stuck in limp mode due to....one of the two items in the title.

When this does occur, it’s on startup...almost always. Although recently it has happened while driving, which means now I really need to address it. Of note, till now at least, I have not experienced any issues with throttle response or drivability. Even now, when the codes are cleared, it feels fine until the moment it kicks into limp mode.

The reason I question whether it’s the TPS or the actuator is that often the code for the actuator itself doesn’t even get thrown. Nearly every time the car goes into limp mode, it’s 27A2. And then of course 2B57. I often see 279B as well.

I will often get 2B15, but not always, probably less than half the time. And, what’s interesting is that it’s always 27A2 and 2B15...which are opposite sides of the engine. I have never gotten 2A15, or 27B2.

I have just received my new USB-OBD cable, so hoping to do some more in-depth testing this weekend...however I’d really like to know ahead of time if these look like one or the other to anyone who’s been through this before. This car must certainly be running out of parts to break...
 

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Discussion Starter #2
To simply above - since this issue started, I have always seen either 2B15, 27A2, or both. Can’t tell which one I see more of, seems nearly 50/50. But I have never received one of the specific TA-failure codes, as far as I know.

Seems to me that 27A2 is almost definitely caused by TPS, and that 2B15 could be caused by TA or TPS...and poor connections on the speciality CAN loop for throttle control could cause either as well. Is this an accurate way of viewing these codes?
 

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I had code 27A1 which is the same but for bank 1. In my case it was throttle actuator and not the sensor which seems to be general consensus for the error code. I found the reason when i removed the plenum and operated the throttle valves by had. Bank 1 actuator was sticking very hard to turn compared to bank 2. Also measured the continuity for wires just in case.
 

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Discussion Starter #4
I see, thanks for the response. There are so many codes related to this subsystem and so many ways for it to go wrong...was hoping to avoid the actuator as it’s such a pain in the *** to replace. But looks like that may be required.
 

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Discussion Starter #5
Quick update - finally was able to get INPA hooked up, however my German is not at all what it used to be - not that it was ever good - so I’m a bit unsure of what some of these are looking at...however I gather given how close the bars are to red in almost every category that these are both on their last legs. Particularly due to the fact that it failed the Integral TV Ramp tests.

Interesting note, the car did start up today in limp mode, which it has now been doing every time, but when I ran the test the first time, both Integral TV Ramp tests passed by a narrow margin. After running the test, the error was gone, and the car was able to be driven normally. So, I went out and did a mix of low-speed cruising around and...some high-speed cruising. Tried to get it to throw the error again, but it would not. After about 20 minutes of that, I came back and ran the test again a few times. This is where the results you see below came from, failing one of the tests.

Just curious as to what others who know more than I are seeing in these results...according to what I’ve seen, this seems to show that they’re completely shot in every way.

Thanks again.

938325


938328
 

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Discussion Starter #6
Just following up in case anyone reads this later on -

Ended up replacing both actuators with rebuilt lifetime warranty units from M Power Motorsports. The gears on both were fairly chewed up. No teeth gone entirely, but frankly I'm surprised they made it ~107k miles.
 
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