well today after a radio installation my car was acting up. It ran fine then would cut off in 3 minute intervals. Then when i drove it the epc light came on and the car ceased, walked out the car, un plugged then re-plugged the ecu back it and it ran for another 3 minutes. now it wont even turn over but it will crank. My cel use to come on when i cut on the ignition, now nothing. I took the ecu apart changed both capacitors and still nothing, need some advice and help. What could it be?? i gave 12 volt signal when from the radio to the can bus and k line. I should have read the diagram before installing the radio. I was trying to find the turn on wire for the amp so i just tested each wire. Bad idea. So now im stuck i dont know where to begin. All my fuses are good and nothing it out of place. Swapped out my ecu with a buddy of mines and it ran. What did i fry on my ecu? help??

ok but what goes bad when that happened?is it something i can replace on the board?