DTC B2420: HL Auto Leveling ECU Failure: Procedure

CHECK FOR DTC
1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Check for DTCs. Refer to DTC CHECK / CLEAR .
  OK
  
  DTC B2420 is not output.
NG → See step 2

OK → See step 3
REPLACE HEADLIGHT LEVELING ECU ASSEMBLY. Refer to REMOVAL
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING