A DC error on an Alpine stereo indicates that the speaker wire is grounded to the vehicle chassis or to any other surface. This malfunction is caused by the speaker cables shorting the electric circuit.
To solve this error, first make sure that the speaker wires are not grounded out. To determine if the wire needs to be replaced or repaired, set the meter to the lowest resistance scale possible. Next, probe the positive side of the lead to the speaker wire while the negative side of the meter lead is grounded. Another possible solution is resetting the cable wires.