To add to my countless problems with this 2001 S40, my transmission just went into "limp" mode I'm assuming…

I was on the freeway when my engine about redlines, but has no power. I let of the throttle and pulled over.
On my adventure home I was only about to go about 20-30 miles an hr…
I can only use reverse, and sometimes the 3rd gear. (While shifting through)
Last summer I have the fluid serviced.

The car has a flashing arrow, and an engine light for p0740, and p0733...

 

PO740 is a TCC circuit malfunction. (Torque convertor)
PO733 Gear Ratio Incorrect.

the torque convertor problem will be causing the 2nd fault.
An electrical failure, probably resulting from a solenoid problem.

see links below: useful information.

P0740 Torque Converter Clutch Circuit Malfunction DTC
P0743 Torque Converter Clutch (TCC) Solenoid Circuit Electrical

 

Now my car will fall out of gear with no notice other than the lack of power, and the rpm raise… I drove it to a shop they could not tell me anything…

Wiring all looks good and I put electric grease to insure all the plugs were in there good. No change.

 

Is the ATFstill a cleanish red color or well overdue for a drain and fill?

Was the correct ATF used when you had it replaced last summer.
The 5 speed transmission must have JWS3309 spec'd fluid or problems occur.