1996 850 R, 120K miles. Transmission recently flushed a few weeks back. Prior conditon of fluid was decent (not burnt).

For the past few weeks, I have been getting the dreaded "flashing arrow".

Temp where I live - between 60-80 degrees in the day.

When it happens: After driving on the highway for 30 minutes or more and then it comes on while driving in the city. Ususally shortly after getting off highway.

What I've done to troubleshoot: My Volvo mechanic has scanned for codes multiple times, and he was even able to replicate the issue. No codes appeared in the system. We replaced the econ/sport switch as a quick, inexpensive fix, but the problem still exists.

What I'm wondering: Next steps to troubleshoot. I know that it could be the PNP switch, but without a code, I'm lost. What else might it be?

The other interesting point: the flashing arrow goes away when I throw it in Sport mode.

The tranny shifts & feels solid (also confirmed by mechanic).

Any help is greatly appreciated! Trying to fix this without spending tons of cash and just trying to guess what the problem is.