There is an ID tag on the back side of the trans case. It is roughly 3.5x1.5" and should be white or pink in color. In the center of the tag there are two larger letters than the rest of the letters on the tag and this is the code that is needed. Just above or next to the letters will be a number that is also larger than the rest of the letters but not as large as the two larger letters and this designates the year. XA or XB are the codes for the GTP and GS until the 04 and then there were a few different ones used.
