Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Light Sensor Circuit Malfunction (B1244)

Toyota Tacoma 2015-2018 Service Manual / Lighting / Lighting System / Light Sensor Circuit Malfunction (B1244)

DESCRIPTION

This DTC is output when a failure of the automatic light control sensor circuit is detected.

DTC Code

DTC Detection Condition

Trouble Area

B1244

When either condition below is met:

  • Malfunction of light sensor
  • Open or short of light sensor circuit
  • Automatic light control sensor
  • Harness or connector
  • Main body ECU (Multiplex network body ECU)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

If the main body ECU (multiplex network body ECU) is replaced, refer to Registration (See page ).*1

  • *1: w/ Smart Key System

PROCEDURE

1.

CHECK FOR DTC

(a) Clear the DTC (See page (b) Recheck for DTC (See page  ). ).

(b) Recheck for DTC (See page OK: ).

OK:

DTC B1244 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

2.

READ VALUE USING TECHSTREAM (LIGHT SENSOR ILLUMINANCE)

(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.

Main Body

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

-

OK:

Output illuminance is as shown in table above.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

3.

CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LIGHT CONTROL SENSOR VOLTAGE)

(a) Disconnect the ECU connector.

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

Standard voltage:

Tester Connection

Switch Condition

Specified Condition

19 (CLTB) - 21 (CLTE)

Ignition switch ON

11 to 14 V

Ignition switch OFF

Below 1 V

Text in Illustration

*a

Component without harness connected

(Main Body ECU (Multiplex Network Body ECU))

NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

OK

4.

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

(a) Disconnect the M6 main body ECU (multiplex network body ECU) connector.

(b) Disconnect the A37 automatic light control sensor connector.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

M6-19 (CLTB) - A37-1 (CLTB)

Always

Below 1 Ω

M6-20 (CLTS) - A37-4 (CLTS)

M6-21 (CLTE) - A37-2 (CLTE)

M6-19 (CLTB) - Body ground

Always

10 kΩ or higher

M6-20 (CLTS) - Body ground

M6-21 (CLTE) - Body ground

OK

REPLACE AUTOMATIC LIGHT CONTROL SENSOR

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Terminals Of Ecu
TERMINALS OF ECU 1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Text in Illustration *1 Main Body ECU (Multiplex Network Body ECU) - - (a ...

Data List / Active Test
DATA LIST / ACTIVE TEST 1. DATA LIST HINT: Using the Techstream to read the Data List allows values or states of switches, sensors, actuators and other items to be read without removing any parts ...

Other materials:

Diagnosis System
DIAGNOSIS SYSTEM 1. CHECK DLC3 (a) The vehicle's ECU uses the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format. Symbols (Terminal No.) Terminal Description Condition ...

Precaution
PRECAUTION 1. PRECAUTION FOR HEADLIGHT BULB REPLACEMENT (a) When any defects such as deformation, cracks, dents, chipping, etc. are identified on the headlight, replace it with a new one. (b) Even if the operation seems to be normal, the fail-safe function may be defective. (c) Since halogen b ...

Freeze Frame Data
FREEZE FRAME DATA DESCRIPTION (a) When a pre-collision system DTC is stored, the millimeter wave radar sensor assembly stores the current vehicle (ECU or sensor) state as Freeze Frame Data. CHECK FREEZE FRAME DATA (a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON. (c ...

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