wifes 2000 s40. Any clue what this could mean? Blinking check engine light. how to diagnose?

 

Blinking Check Engine light means misfire.
It could be the spark plus or coils and wires or all 3 of them.

 

prolly one bad coil. plug in a reader and see what you get.

 

i was under the impression with most american made cars a blinking check engine light ment you should stop driving the vehichle i have owned my 2000 volvo s40 for awhile now but not too familiar with working on them too much yet