I was driving to work today and the VSA and cel came on and the screen said something about brakes.. I turned the car off and on and the code 2138 came on...I believe it has to do with the APP sensor...The reason I recently purchased the TL was because my tahoe was going in to limp mode and throwing this code... I have had the car one month and I currently have the tahoe with the same problem.....I'm sooooo tired of throwing parts at cars.....worth changing the APP sensor myself? what is the exact part number for 2007 tl APP sensor?

 

Oh yes one more important piece of info.....the car NEVER went into limp mode. It drove fine!