DTC B1556: Extension Module Malfunction 2 [10/2019 - 07/2022]: Procedure

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [10/2018 - 10/2020] Refer to DTC CHECK / CLEAR [10/2020 - 07/2022]

   Body Electrical > Navigation System > Clear DTCs 

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

   Refer to DTC CHECK / CLEAR [10/2018 - 10/2020] Refer to DTC CHECK / CLEAR [10/2020 - 07/2022]

   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 [10/2018 - ] 

Result: 

NG 

REPLACE NAVIGATION ECU. Refer to  REMOVAL [10/2019 - 07/2022]