Test E: Loud Popping Sound When Cycling the Ignition

PINPOINT TEST E: LOUD POPPING SOUND WHEN CYCLING THE IGNITION

E1-E2:

E2-E5:

E5 Continued:

Normal Operation
The START input circuit 1786 (BN/PK) is sent to the audio unit when the ignition switch is turned to the START position. The audio unit then immediately mutes all speaker amplifier outputs and the subwoofer amplifier enable circuit output to eliminate the possibility of speaker pops during engine cranking.

Possible Causes
- Circuit 174 (GY/BK) short to voltage
- Circuit 1786 (BN/PK) short to voltage
- Subwoofer amplifier
- Audio unit
- Smart junction box (SJB)