Lacrosse P0068, P0101 gremlins...

Dcool

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Buick Ownership
2005 lacrosse
2005 LaCrosse CX 206K miles and well maintained. I bought this from second owner and it runs great then unexpectedly goes into limp-mode. I clear code with my cheap scanner and it runs fine until the next random episode (I carry my cheap code reader with me for this purpose!) Codes are P0068, P0101, (MAF,MAP,TPS). I have replaced the MAP, MAP, PCV. Car is 100% stock. The only thing I haven't replaced is the TPS as it is built-into the throttle body and GM Parts (AC Delco) online shows the TB is out of stock. Anyone that has ideas are welcome for your thoughts on this. Thanks in advance!
 
It does appear those codes are checking for the relative feedback values between the MAF, MAP & TPS. Your scanner might have the ability for you to monitor the TPS position in real time. You can also monitor the output voltage (using an oscilloscope is the best method). Or of course you can just try to replace the sensor.

The throttle Position sensor shows as being available from after market parts sellers such as AutoZone (and other parts retailers). I show links here for both the 3.6L & the 3.8L TPS, though I think your engine is likely a 3.8L.


 
Yes, is't the 3800 V6. However, the TPS is integrated into the TB: it's not a stand-alone sensor. Looks like GM doesn't support parts for this as a replacement TB is N/A. I may have to search Pick-A-Part for a used one from a low-mileage wreck. It's a shame as this car runs great otherwise and only uses 1/2 qt. oil / 3000 miles and I get 31 mpg highway...
 
Yes, is't the 3800 V6. However, the TPS is integrated into the TB: it's not a stand-alone sensor. Looks like GM doesn't support parts for this as a replacement TB is N/A. I may have to search Pick-A-Part for a used one from a low-mileage wreck. It's a shame as this car runs great otherwise and only uses 1/2 qt. oil / 3000 miles and I get 31 mpg highway...
I'm not familiar with a GM production 3.8L where the TPS is not the same as the one shown in the links that I posted. So, on the end of the throttle shaft (opposite the throttle cable side), there is not a TPS with two mounting screws?

Could you post photos of that end of the throttle shaft?
 
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Sorry I am new to this forum and don't seem to know how to post a picture here...
 
I'm not familiar with a GM production 3.8L where the TPS is not the same as the one shown in the links that I posted. So, on the end of the throttle shaft (opposite the throttle cable side), there is not a TPS with two mounting screws?

Could you post photos of that end of the throttle shaft?
here it is...
 

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Thanks to both of you for sharing. I did not know that GM installed Drive by wire on any of the 3.8L. Please let us know what he finds.
 
New/Rebuilt replacements all seem to be out of stock & nothing available unless you can find a used one at a Pick&Pull/JY! This is a sad story & IIRC, this has already been mentioned here before!
 
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New/Rebuilt replacements all seem to be out of stock & nothing available unless you can find a used one at a Pick&Pull/JY! This is a sad story & IIRC, this has already been mentioned here before!
Sad indeed. Makes me want to stay away from owning the series III. I just don't think that I could be at ease with an engine that uses drive by wire.
 
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Sad indeed. Makes me want to stay away from owning the series III. I just don't think that I could be at ease with an engine that uses drive by wire.
My 2003 Camry 4 cylinder uses drive by wire and it works very well.
The big plus with the Series III is the aluminum UIM.
 
OK everyone, Its the integrated TPS on the TB.. Anyone tried the Cart done TB??? Mechanic says they havent't had a lot of luck with them...
 
Cardone has them remanufactured. Fuel Injection Throttle Body - 6E-3023
Have you (or anyone here) used Cardone? Mechanic confirmed TPS on the TB causing the issue. They say they haven't had much luck with their products.
 
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As an Amazon Prime frequent user, normally they give you a free 30-day return on any purchase. That has been extended to 60-days during the Holiday season, after that you are SOL. If you order a rebuilt replacement, look at the fine print on the box that should show the country of origin. I have been getting ACDELCO parts made in China!! Did Cardone also outsource their part rebuilds?? I would look @ the fine print on the box if you order one?
 
OK everyone that responded, Thank You.

I found a used TB on Ebay ($!119) which should deliver next week. Mechanic did a diagnostic (2 days worth) last week and confirmed it is the integrated TPS, They have had poor success with aftermarket (Cardone, Dorman, etc which sell for $300+).

In review, it seems the problem usually happens after driving under a sustained load such as pulling a long hill and then coasting while going down the other side. DTC 's set is CEL, stability control, and reduced engine power (limp-mode). Interim solution is to keep my cheap Harbor Freight code reader handy and clear the code which takes it out of limp-mode and then the car runs fine. Once the replacement TB arrives I will RR.

I'm curious to how many Series 3 3800 owners out there with high mileage (>200K miles) have NOT had this issue. Anyone with +300K miles??

Thanks again!
 
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