Unknown issues.
 

I have a 2006 s40. It has 153k miles on it. I am not the original owner. When I got the car I was told that if it wouldn't go over 20mph to stop shut it off wait about 10 seconds and restart it. That has worked the few times it has done it. The abs light it on. We have checked everything and run codes but cannot find the reason it is on. The anti skid light comes on when I drive over 15 mph. The CEL is not on. I have noticed if it is 60 degrees or below I dont have this problem but if it is over 60 degrees outside I do have issues. Yesterday I got in the car and spent 20 mins stopping and starting but it would not let me go over 20 mph. We are at a loss as to what it can be. TIA for any help or advice.

Sounds like your car is going into limp mode where the ECU is trying to minimize any damage to the car. This can be triggered by fault codes from the ABS and transmission computers. Those typically get inputs from the wheel speed sensors (common cause) but sometimes the problem can be in the computer boards due to cracked solder joints or other components like the steering angle sensor. Note that not all OBD2 sensors can read proprietary fault codes or the chassis codes (ie for the ABS and the SRS systems) so you may need to go to a Volvo dealer or a certified Vovlo tech with access to the VIDA DICE tools. For starters, you can google or search Youtube on ABS computer problems (Rochatek and Midwest ABS are two shops that rebuild the boards) and on symptoms of a bad steering angle sensor. I'd be willing to bet if you fix the TRACS/ABS issue, you car will go back to full power.

My husband was checking different things last night and the alert for routine maintenance popped up we just got the filter in to change the oil today could that have something to do with it?

An oil change notice won't cause any of the problems you're seeing now.

MT6127's advice is golden... I'd suggest doing just what he said.