If the code does not clear at all, it's a bad ECM. You're done here.
The reason is because the system needs to run a self test. The code should clear and the test should take about six seconds to run. If the code never clears, that means the ECM is unable to even start the test because it has an internal failure. Write it up for an ECM and you'll be right 90% of the time.
If the
code clears, but comes back after a few seconds, the problem is most likely in the squib or clockspring. Very unlikely that it's the wiring, but we'll get to that.
That's because the ECM successfully ran its test and found a fault.