Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000025DHJ
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 - 11/2022]
Title: LIGHTING (EXT): LIGHTING SYSTEM (for TMMMS Made): B1244; Light Sensor Circuit; 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]

DTC

B1244

Light Sensor Circuit

DESCRIPTION

The automatic light control sensor detects ambient light. The sensor creates an electrical signal based on the amount of light detected, and sends the signal to the main body ECU (multiplex network body ECU). The main body ECU (multiplex network body ECU) turns on or off the headlights and taillights according to the signal.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B1244

Light Sensor Circuit

Detection condition:

  • The ignition switch is ON.

Malfunction status:

  • Either of the following conditions is met:
    • Malfunction in automatic light control sensor
    • Open or short in automatic light control sensor circuit

Malfunction duration:

  • 5 seconds or more
  • Automatic light control sensor
  • Harness or connector
  • Main body ECU (multiplex network body ECU)

Main Body

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Registration.*

Click here 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function (Gasoline Model, TMMMS Made)): REGISTRATION

  • *: w/ Smart Key System

PROCEDURE

1.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > Main Body > Clear DTCs

NEXT

2.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

(f) Check for DTCs.

Body Electrical > Main Body > Trouble Codes

OK:

DTC B1244 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

3.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) According to the display on the Techstream, read the Data List and check that the value of Light Sensor Illuminance changes while performing the following:

(1) Cover the automatic light control sensor with an opaque object.

(2) Slowly move the opaque object to uncover and then cover the automatic light control sensor.

Body Electrical > Main Body > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Light Sensor Illuminance

Light control sensor illuminance

0 to 8191 lx or SensorFail

Value is output according to ambient light level

The displayed value is "0" when no light is detected.

Body Electrical > Main Body > Data List

Tester Display

Light Sensor Illuminance

OK:

The value changes according to the amount the automatic light control sensor is covered.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

4.

CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the h1 automatic light control sensor connector.

(b) Disconnect the I85 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

h1-1 (CLTB) - I85-23 (CLTB)

Always

Below 1 Ω

h1-4 (CLTS) - I85-24 (CLTS)

Always

Below 1 Ω

h1-2 (CLTE) - I85-25 (CLTE)

Always

Below 1 Ω

h1-1 (CLTB) or I85-23 (CLTB) - Body ground

Always

10 kΩ or higher

h1-4 (CLTS) or I85-24 (CLTS) - Body ground

Always

10 kΩ or higher

h1-2 (CLTE) or I85-25 (CLTE) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

*a

Component with harness connected

(Main Body ECU (Multiplex Network Body ECU))

(a) Connect the I85 main body ECU (multiplex network body ECU) connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I85-23 (CLTB) - I85-25 (CLTE)

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V
NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

OK

6.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) Inspect the automatic light control sensor.

Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; LIGHTING (EXT): AUTOMATIC LIGHT CONTROL SENSOR: ON-VEHICLE INSPECTION

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE AUTOMATIC LIGHT CONTROL SENSOR