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Home >> Toyota >> 2021 >> Highlander LE, FWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Headlights >> Lighting System (W/ AFS) - Diagnostic Codes (1 Of 2) >> LIGHTING SYSTEM (w/ AFS) >> DTC B242C-04: Headlight Control Module (Sub) System Internal Failure; DTC B242D-04: Headlight Control Module (Main) System Internal Failure [11/2023 - ] >> Description
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DTC B242C-04: Headlight Control Module (Sub) System Internal Failure; DTC B242D-04: Headlight Control Module (Main) System Internal Failure [11/2023 - ]: Description

The headlight ECU sub-assembly LH or headlight ECU sub-assembly RH stores a DTC if it detects an internal malfunction.

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
B242C-04 Headlight Control Module (Sub) System Internal Failure Detection condition: 
  1. The ignition switch is ON

Malfunction status: 

  1. Headlight ECU sub-assembly RH internal malfunction

Malfunction duration: 

  1. Maximum 15 minutes
Headlight ECU sub-assembly RH Headlight Control (Sub)
B242D-04 Headlight Control Module (Main) System Internal Failure Detection condition: 
  1. The ignition switch is ON

Malfunction status: 

  1. Headlight ECU sub-assembly LH internal malfunction

Malfunction duration: 

  1. Maximum 15 minutes
Headlight ECU sub-assembly LH Headlight Control