DTC B1556: Extension Module Malfunction 2 [12/2019 - 10/2022]: Procedure

1. Clear the DTCs.

   Body Electrical > Navigation System > Clear DTCs 

2. Recheck for DTCs and check that no DTCs are output.

   Body Electrical > Navigation System > Trouble Codes 

   OK

   No DTCs are output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

NG 

REPLACE NAVIGATION ECU. Refer to  REMOVAL [12/2019 - 10/2022]