Voltage check came back fine. I have on order another solenoid, so I'm just gonna change the oil again for now. I just bought the car not too long ago. I never bothered to ask if the car was running snythetic. I just drained whatever was in it, then loaded up with 10w-30. CEL didn't happen till about 1200-1500 miles into the change. If this engine HAD a different weight oil, or synthetic, would that cause this problem without a proper engine flush?