DTC B15A1: Audio HU Malfunction; DTC B15B3: Radio Tuner Malfunction; DTC B15B4: CD Changer Malfunction; DTC B15B5: DVD Changer Malfunction; DTC B15B7: Bluetooth Module Malfunction: Procedure

CHECK DTC
1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Recheck for DTCs and check if the same DTC is output again.
  OK
  
  No DTCs are output.
NG → See step 3

OK → See step 2
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
REPLACE RADIO RECEIVER ASSEMBLY. Refer to REMOVAL