2000 Montana transmission swap

[2000montana]

I have a 2000 Pontiac Montana and a few weeks ago my transmission (4T65E) failed so I replaced it with a transmission out of a 2003 Pontiac Aztec.

As far as I can tell the final drive / gear ratios are the same, but I could be mistaken.

I am getting a fault code of P1810 (TFP position sensor) from the PCM and it is also getting torque lockup occasionally.

Apparently sometime in 2002 the TFP assembly was updated (TSB #020730050) and I am concerned that my PCM need to be reprogrammed to accommodate this change.

The transmission is in what I presume limp mode and I don’t get top gear. Although on one particular day (just as the first fault code first registered) it was shifting in all gears.

Hopefully you can help with the above problem.

[troy1]

In 2003 the PCS and pressure manifold switch maybe different. The neutral safety switch should have been inside the trans on the 03 and your old one was on top of the case. I would say that 00 and 03 are not exchangeable do these changes. Did the junk yard recommend the swap?