"ABS/STC Service Required" and check engine light on
 

hey all!
i'm new to my volvo ('02 V70 T5 A) and new to this forum. i'm posting to ask if anyone has experienced/heard of/has any input on what's happening right now. today and yesterday my has given me two messages. "ABS Service Required" and "STC Service Required". yesterday they appeared for about 30 minutes and then went away on their own after i had turned off the car. towards the end of my drive to work today the "ABS" message turned on again along with the check engine light, which did not appear previously. there does not seem to be any difference in the way that it drives. whats going on??