Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: Headlight Control Module (Sub) System Internal Failure (B242C04,B242D04)

Toyota Corolla Cross (2022-2025) Service Manual / Vehicle Exterior / Lighting (ext) / Lighting System (w/ Afs) / Headlight Control Module (Sub) System Internal Failure (B242C04,B242D04)

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

B242C04

Headlight Control Module (Sub) System Internal Failure

 Detection condition:
  • The ignition switch is ON
Malfunction status:
  • Headlight ECU sub-assembly RH internal malfunction
Malfunction duration:
  • Maximum 15 minutes

Headlight ECU sub-assembly RH

B242D04

Headlight Control Module (Main) System Internal Failure

 Detection condition:
  • The ignition switch is ON
Malfunction status:
  • Headlight ECU sub-assembly LH internal malfunction
Malfunction duration:
  • Maximum 15 minutes

Headlight ECU sub-assembly LH

CAUTION / NOTICE / HINT

NOTICE:

If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight ECU sub-assembly LH.

Click here

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Headlight Control > Clear DTCs Body Electrical > Headlight Control (Sub) > Clear DTCs
NEXT

2.

CHECK FOR DTC

(a) Turn the ignition switch to ON.

(b) Wait at least 15 minutes.

(c) Check for DTCs.

Body Electrical > Headlight Control > Trouble Codes Body Electrical > Headlight Control (Sub) > Trouble Codes

OK:

DTC B242C04 and B242D04 are not output.

Result

Proceed to

DTCs are not output

A

B242C04 is output

B

B242D04 is output

C
A

USE SIMULATION METHOD TO CHECK

B

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

C

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

    READ NEXT:

     IG Circuit Short to Ground or Open (B242E14)

    DESCRIPTION The headlight ECU sub-assembly operates using the power source voltage input from the IGR terminal and ECUB terminal. The IG terminal power source voltage is supplied by turning the IGR-N

     ECUB Circuit Short to Ground or Open (B242F14)

    DESCRIPTION The headlight ECU sub-assembly operates using the power source voltage input from the IGR terminal and ECUB terminal. The power source voltage of the ECUB terminal is supplied when the ma

     Headlight Source LH Malfunction (B243900,B243A00)

    DESCRIPTION The headlight ECU sub-assembly LH and headlight ECU sub-assembly RH internally boost the power supply voltage to ensure a constant supplied current for the Lo/Hi beam LED of their respecti

    SEE MORE:

     Ignition Circuit

    DESCRIPTION A direct ignition system is used on this vehicle. The direct ignition system is a 1 cylinder ignition system which ignites one cylinder with one ignition coil. In the 1 cylinder ignition system, one spark plug is connected to the end of the secondary winding. High voltage is generated in

     Removal

    REMOVAL CAUTION / NOTICE / HINT COMPONENTS (REMOVAL) Procedure Part Name Code 1 BACK DOOR TRIM UPPER PANEL ASSEMBLY 64790B - - - 2 BACK DOOR SIDE GARNISH LH 67938A - - - 3 BACK DOOR SIDE GARNISH RH 67937B - -

    © 2020-2025 Copyright www.tcorollacross.com