I have a misfire code in cylinder 3. I have replaced the plugs and wires, but the problem is still there. How can I check the module on cylinder 3? Is there a way to isolate it or switch it with the one on cylinder 4?
-kevin

 

Yes, you can swap the coils on #3 and #4 easily. They are held down with 10mm bolts. Careful with the electrical connectors. The little round prongs tend to back out of the plastic and can cause a misfire simply for a bad connection.

In my experience with a 2001 S40, the coils tested fine on an ohmmeter and still caused a misfire. I only found this when biting the bullet and purchasing 2 new coils.

The last time I bough coils Autozone sold genuine Volvo coils for about $45 USD.

Ignore the red circle in this picture (thats the fuel pressure regulator). The coils are located under the plastic engine cover and are seen in the top part of this picture.