My 2000 S40 has 105K miles and never had a transmission service. The fluid is very dark and yesterday I started the car,the check engine light came on,the arrow next to it was flashing and the car didnt have power taking off as if it was stuck in 2nd or 3rd gear. drove it for 1 or 2 miles,turned off.restarted went back and forth on my driveway a few times and tranny unlocked,getting full power again. Disconnected battery,arrow on dashboard stopped flashing and disappeared,just the check engine light still on. Will have to get the scanner see the code and erase it.
My question is : what could have caused the problem? The fact the fluid is still original could have caused it? Should I have it changed? Tks