Lexus ES manuals

Lexus ES: Open in IG Circuit (B242E)

DESCRIPTION

The headlight ECU sub-assembly operates using the power source voltage input from the IG terminal and ECUB terminal.

The IG terminal power source voltage is supplied by turning the IG1-NO. 1 relay to ON.

The headlight ECU sub-assembly receives engine switch on (IG) signals from the main body ECU (multiplex network body ECU) via CAN communication, compares the engine switch on (IG) signal and the power source voltage supply condition of the IG terminal and monitors the result.

for LED Type Turn Signal Light

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B242E

Open in IG Circuit

  • The engine switch is on (IG).
  • When the IG terminal power source voltage is 0 V (engine switch off), IG ON signals from the main body ECU (multiplex network body ECU) via CAN communication are continuously received
  • 10 seconds or more
  • Headlight ECU sub-assembly LH
  • Harness or connector

AFS

for LED Type Turn Signal Light

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B242E

Open in IG Circuit

  • The engine switch is on (IG).
  • When the IG terminal power source voltage is 0 V (engine switch off), IG ON signals from the main body ECU (multiplex network body ECU) via CAN communication are continuously received
  • 10 seconds or more
  • Headlight ECU sub-assembly RH
  • Harness or connector

AFS (Sub)

for Bulb Type Turn Signal Light

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B242E

Open in IG Circuit

  • The engine switch is on (IG).
  • When the IG terminal power source voltage is 0 V (engine switch off), IG ON signals from the main body ECU (multiplex network body ECU) via CAN communication are continuously received
  • 10 seconds or more
  • Headlight ECU sub-assembly LH
  • Harness or connector

HL AutoLeveling

for Bulb Type Turn Signal Light

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B242E

Open in IG Circuit

  • The engine switch is on (IG).
  • When the IG terminal power source voltage is 0 V (engine switch off), IG ON signals from the main body ECU (multiplex network body ECU) via CAN communication are continuously received
  • 10 seconds or more
  • Headlight ECU sub-assembly RH
  • Harness or connector

HL AutoLeveling (Sub)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • 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.*1

    Click here

  • If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information the headlight ECU sub-assembly LH.*2

    Click here

  • When replacing the headlight ECU sub-assembly LH, always replace it with a new one. If a headlight ECU sub-assembly LH which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.
    • *1: for LED Type Turn Signal Light
    • *2: for Bulb Type Turn Signal Light

PROCEDURE

1.

CONFIRM MODEL

(a) Choose the model to be inspected.

Result

Proceed to

for LED Type Turn Signal Light

A

for Bulb Type Turn Signal Light

B

B

GO TO STEP 4

A

2.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > AFS > Clear DTCs Body Electrical > AFS (Sub) > Clear DTCs
NEXT

3.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.

(f) Check for DTCs.

Body Electrical > AFS > Trouble Codes Body Electrical > AFS (Sub) > Trouble Codes

OK:

DTC B242E is not output.

Result

Proceed to

OK

A

NG (DTC output from headlight ECU sub-assembly LH)

B

NG (DTC output from headlight ECU sub-assembly RH)

C

A

USE SIMULATION METHOD TO CHECK

B

GO TO STEP 6

C

GO TO STEP 8

4.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs Body Electrical > HL AutoLeveling (Sub) > Clear DTCs
NEXT

5.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(f) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes Body Electrical > HL AutoLeveling (Sub) > Trouble Codes

OK:

DTC B242E is not output.

Result

Proceed to

OK

A

NG (DTC output from headlight ECU sub-assembly LH)

B

NG (DTC output from headlight ECU sub-assembly RH)

C

A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 8

B

6.

INSPECT HEADLIGHT ECU SUB-ASSEMBLY LH (IG TERMINAL VOLTAGE)

*a

Front view of wire harness connector

(to Headlight ECU Sub-assembly LH)

(a) Disconnect the A78 headlight ECU sub-assembly LH connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A78-4 (IG) - Body ground

Engine switch on (IG)

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.

CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - BODY GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A78-12 (GND) - Body ground

Always

Below 1 Ω

OK

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.

INSPECT HEADLIGHT ECU SUB-ASSEMBLY RH (IG TERMINAL VOLTAGE)

*a

Front view of wire harness connector

(to Headlight ECU Sub-assembly RH)

(a) Disconnect the A79 headlight ECU sub-assembly RH connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A79-4 (IG) - Body ground

Engine switch on (IG)

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.

CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY RH - BODY GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A79-12 (GND) - Body ground

Always

Below 1 Ω

OK

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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