So I have a 2004 Honda Civic Ex that won't start, it all started when I replaced my battery, I purchased a refurbished battery because I couldn't afford a brand new one at the moment. It worked, but then I got a check engine light, I scanned it and I had a P0340, which was a faulty cam shaft sensor. I have no idea if this was caused by the battery. Anyways, I replaced the cam shaft sensor with a cheap ebay one, it didnt work but my car was still starting at that point, but I was still getting that CEL, so I parked my car and ordered a more quality sensor, I replaced it once again and after I assembled everything back, my car isn't starting. I will put a link to a video of me trying to start the car and what appears on the cluster.

 

does it crank?

 

Yes it cranks.

 

So I did some diagnosing and come to find out one of the fuses located under the hood for the Ecu was blown. I replaced that and the car fired right up. Now I have another issue that I’m trying to get to the bottom of. What does it mean when the check engine light blinks when I have the Key on the ON position. That seems to be the only time it blinks, because when I turn the engine on, the check engine light goes away. Could it be that a check engine code hasn't been stored in the ECU.

 

Is it the Maintenance Required light or the Check Engine Light?