Hi all, Newbie here but have been lurking about for a while. I have a 2000 V70 AWD XC. I just replaced the automatic transmission with one from a local wrecking yard. Reverse went out in the old one. The first test drive (about 1 mile) went fine until I turned around and started home. Flashing 'up arrow' and check engine light came on and the transmission started out in high gear (limp mode ?) Got back to shop and plugged in my code reader. P1618, Fault on Lead Between AW-50-52, Motroic 4.3. I changed the PNP switch, but no luck.
On several other test drive attempts in the last few days it will occasionally shift as expected only to go into the mode as described above. I talked to the service manager at the local Volvo dealer and he thinks the transmission control module (TCM) needs to be reprogrammed (flashed). Are there other things I should check before taking it to the dealer (expensive)?