Update... Pulled every fuse, one by one and put the key in ACC and same issue each time. The other symptoms I'm getting are while the key is in ACC, the lights (interior and exterior) are flashing like turn signals and I can hear a relay clicking. Also, there's an occasional thump coming from the same area under the passenger seat I heard the pop. I'm now thinking I fried some kind of relay/junction box.

Is there any kind of peripheral computer that's located under the passenger seat. Is there just the one PCM in the engine compartment or are there separate controllers for the ABS and TCS?

Sorry for so many questions! I'm familiar with cheaper (simpler) cars. This is way too much electronics for me! Done some searching, but not finding anything relevant.

Thanks again!