Test K: Loud Popping Sound When Cycling The Ignition Switch - Navigation

PINPOINT TEST K: LOUD POPPING SOUND WHEN CYCLING THE IGNITION SWITCH - NAVIGATION

K1:

K1-K4:

Normal Operation
When the key is placed in START, voltage is sent to the audio unit through circuit 1000 (RD/BK). After the key is removed from START, the audio unit sends an enable signal to the audio amplifier for the subwoofer through circuit 173 (DG/VT), and for all other speakers through circuit 174 (GY/BK). This prevents a voltage surge in the speaker circuits, which could result in a popping noise.

Possible Causes
- Fuse
- Circuit 173 (DG/VT) short to voltage
- Circuit 174 (GY/BK) short to voltage
- Circuit 1000 (RD/BK) open
- Circuit 1522 (DG) open
- Audio amplifier
- Audio unit