Toyota CH-R Service Manual: Light Sensor Circuit Malfunction (B1244)

Toyota CH-R Service Manual / Lighting (ext) / Lighting System / Light Sensor Circuit Malfunction (B1244)

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

Note

B1244

Light Sensor Circuit Malfunction

Any of the following conditions is met:

  • Malfunction in automatic light control sensor
  • Open in automatic light control sensor circuit
  • Short in automatic light control sensor circuit
  • Automatic light control sensor
  • Harness or connector
  • Main body ECU (multiplex network body ECU)

-
DTC Detection Conditions:
 

Vehicle Condition

Pattern 1

Pattern 2

Pattern 3

Diagnosis Condition

Ignition switch ON

○

○

○

Malfunction Status

Malfunction in automatic light control sensor

○

-

-

Open in automatic light control sensor circuit

-

○

-

Short in automatic light control sensor circuit

-

-

○

Detection Time

-

-

-

Number of Trips

1 trip

1 trip

1 trip

HINT:

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Registration.*1

Click here

  • *1: w/ Smart Key System

PROCEDURE

1.

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) Read the Data List according to the display on the Techstream.

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

Value is output according to ambient light level

-
Body Electrical > Main Body > Data List

Tester Display

Light Sensor Illuminance

OK:

Normal condition listed above is displayed.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

2.

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

(a) Disconnect the G1 automatic light control sensor connector.

(b) Disconnect the F15 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

F15-21 (CLTE) - G1-2 (CLTE)

Always

Below 1 Ω

F15-20 (CLTS) - G1-4 (CLTS)

Always

Below 1 Ω

F15-19 (CLTB) - G1-1 (CLTB)

Always

Below 1 Ω

F15-21 (CLTE) or G1-2 (CLTE) - Body ground

Always

10 kΩ or higher

F15-20 (CLTS) or G1-4 (CLTS) - Body ground

Always

10 kΩ or higher

F15-19 (CLTB) or G1-1 (CLTB) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Reconnect the F15 main body ECU (multiplex network body ECU) connector.

*a

Component with harness connected

(Main Body ECU (Multiplex Network Body ECU))

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

F15-19 (CLTB) - F15-21 (CLTE)

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V
NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

OK

4.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) Reconnect the G1 automatic light control sensor connector.

*a

Component with harness connected

(Automatic Light Control Sensor)

(b) Connect an oscilloscope to the automatic light control sensor connector.

(c) Check the waveform.

OK:

Tester Connection

Tool Setting

Condition

Specified Condition

G1-2 (CLTE) - G1-4 (CLTS)

2 V/DIV., 10 ms./DIV.

Ignition switch ON, light control switch in AUTO position

Correct waveform is as shown

HINT:

The communication waveform changes according to the surrounding brightness.
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE AUTOMATIC LIGHT CONTROL SENSOR

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