Toyota Venza manuals

Toyota Venza: Light Sensor Circuit Malfunction (B1244)

Toyota Venza Service Manual / Lighting (ext) / Lighting System / Light Sensor Circuit Malfunction (B1244)

DESCRIPTION

The automatic light control sensor detects ambient light, converts it into an electrical signal, and outputs it to the main body ECU (driver side junction block assembly). The main body ECU (driver side junction block assembly) turns on or off the headlights and taillights according to the signal.

DTC No.

DTC Detecting Condition

Trouble Area

B1244

  • Malfunction in automatic light control sensor
  • Open or short in automatic light control sensor circuit
  • Automatic light control sensor
  • Harness or connector
  • Main body ECU (driver side junction block assembly)

WIRING DIAGRAM


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) Select the following menu items: Body Electrical / Main Body / Data List.

(e) Read the display on Techstream.

Main Body

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Illumination Rate Info

Illumination rate information/0 ms to 99.99 ms

Value is output according to ambient light levels

-

OK:

Normal condition listed above is displayed.


OK

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


NG

2.

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

(a) Disconnect the F4 automatic light control sensor connector.

(b) Disconnect the D49 main body ECU (driver side junction block assembly) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D49-18 (CLTE) - F4-3 (CLTE)

Always

Below 1 Ω

D49-19 (CLTS) - F4-5 (CLTS)

Always

Below 1 Ω

D49-20 (CLTB) - F4-6 (CLTB)

Always

Below 1 Ω

D49-18 (CLTE) - Body ground

Always

10 kΩ or higher

D49-19 (CLTS) - Body ground

Always

10 kΩ or higher

D49-20 (CLTB) - Body ground

Always

10 kΩ or higher


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR


OK

3.

INSPECT MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

(a) Reconnect the D49 main body ECU (driver side junction block assembly) connector.

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

Text in Illustration

*1

Component with harness connected

(Main Body ECU (Driver Side Junction Block Assembly))

-

-

Standard Voltage:

Tester Connection

Condition

Specified Condition

D49-20 (CLTB) - D49-18 (CLTE)

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V

Standard Resistance:

Tester Connection

Condition

Specified Condition

D49-18 (CLTE) - Body ground

Always

Below 1 Ω


NG

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


OK

4.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) Reconnect the F4 automatic light control sensor connector.


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

Text in Illustration

*1

Component with harness connected

(Automatic Light Control Sensor)

(c) Check the waveform.

OK:

Tester Connection

Tool Setting

Condition

Specified Condition

F4-3 (CLTE) - F4-5 (CLTS)

5 V/DIV., 5 ms./DIV.

Ignition switch ON, light control switch in AUTO position

Correct waveform is as shown

HINT:

If the ambient light becomes brighter, width A becomes narrower.



OK

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


NG

REPLACE AUTOMATIC LIGHT CONTROL SENSOR

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