Electronic Engine Control fuse blows when key is turned to start position

111 - No faults detected. If this is your very first code, then there are no active codes.
135 - idle validation switch fault. This is part of your throttle pedal and should not cause a no start.
224 - KAM corrupt. Keep alive memory or power supply. I have seen this and usually does not cause a no start but is also part of bad power supply.
622 - Engine using field default. ECM memory fault will cause the ECM to use base programming.
615 - Programmable parameters KAM corrupt. This is also an internal ECM memory failure.

These last codes are ECM related and can be caused from too low, too high supply voltage, bad grounds, or an internal ECM failure.

The ECM is mounted at the firewall on the left hand side. Should have a long skinny gray connector that takes a 3/8" or 10mm socket to remove, (I think). Disconnect this connector and see if the fuse blows or not. If it still blows with the ECM disconnected, the ECM should be fine and you need to locate the short somewhere between the fuse panel and the ECM connector. If it does not blow with the ECM disconnected, then I am sorry to say you probably have an internal ECM failure. With the key on, you should have battery power at pins 1, 37 and 57. Ground is at pins 40 and 60.

 

The pin number locations should be molded into the plastic connector body. They are very tiny and hard to see. If the fuse is blowing only with the ECM plugged in, I would say it is shorted internally. You can get them through your local dealer, but I recommend a salvage yard.