I haven't had any error codes after reconnecting the power. I use the stock door speakers, no after market amp.
I'm almost sure there is no testing of the connected speakers. While installing I tested the 4 channels one-by-one with my own (16 Ohm) speaker to make sure I got the correct channels (1x Left + 1x Right) to the sub.
BTW: I'm not using the pioneer sub anymore, I didn't like the sound of it much. I cannot recommend it for EDM.
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