The "Check Engine Light" would continually keep coming on after driving 40 to 60 miles. The code indicated that I had a random misfire in various different cylinders. I replaced the ignition wires, rotor, rotor cap, new plugs, with OEM and still had the recurring problem. I took it to a volvo repair shop and after 2 days and $150 they told me I needed a new engine. The Check Engine Light was annoying but the uncleared codes in the car's computer would not allow me to get it through smog check in California even though the car ran great with no evidence of a misfire. Anyway, a couple of days ago I got a new code, "Engine Crank Sensor" appeared. I bought a new sensor at my local auto parts store for $66 and installed it in about 45 minutes. The check engine light is no longer coming on and after driving 120 miles all the codes have been cleared out of the car's computer and it has passed smog. In my V70 the sensor is located below the distributor cap and attached to the bell housing with one 11 mm bolt. Hope this helps.