Toyota Sienna Service Manual: Light Sensor Circuit Malfunction
DTC B1244 Light Sensor Circuit Malfunction
DESCRIPTION
This DTC is output when failure in the light sensor circuit is detected.
DTC No. |
DTC Detection Condition |
Trouble Area |
B1244 |
- Malfunction of automatic light control sensor
- Open or short of automatic light control sensor
circuit
|
- Automatic light control sensor
- Harness or connector
- Multiplex network body ECU
|
WIRING DIAGRAM

INSPECTION PROCEDURE
1 READ VALUE OF INTELLIGENT TESTER
- Connect the intelligent tester to DLC3.
- Turn the ignition switch ON and push the intelligent
tester main switch ON.
- Select the items below in the DATA LIST, and read the
displays on the intelligent tester
BODY NO.1:

2 CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK BODY ECU - AUTOMATIC
LIGHT CONTROL SENSOR)
- Check for open or short circuit in the harness and the connector between
the terminal 6 of the automatic light control sensor and the terminal B6-6
of the multiplex network body ECU.
- Check for open or short circuit in the harness and the connector
between the terminal 3 of the automatic light control sensor and the
terminal B6-4 of the multiplex network body ECU.
- Check for open or short circuit in the harness and the
connector between the terminal 5 of the automatic light
control sensor and the terminal B6-5 of the multiplex
network body ECU
3 INSPECT AUTOMATIC LIGHT CONTROL SENSOR
- Measure voltage between the terminal 3 and the terminal
5 of the automatic light control sensor
Standard

4 INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
- Measure voltage between the terminal B6-6 and the
terminal B6-4 of the multiplex network body ECU in the
instrument panel junction block assembly.

Voltage

REPLACE AUTOMATIC LIGHT CONTROL SENSOR
1. DTC CHECK
If a malfunction code is displayed during the DTC check ,
check the suspected area listed for that code in the table
below, and proceed to the appropriate page.
DIAGNOSTIC TROUBLE COD ...
DESCRIPTION
The Multiplex network body ECU receives the ACC and IG signals from the
ignition switch.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 READ VALUE OF INTELLIGENT TESTER
Connect the in ...
Other materials:
Adjustment
HINT:
If the malfunction does not disappear by following the
procedure in ADJUSTMENT and the rear No. 2 seat
assembly needs to be replaced, do not disassemble the rear
No. 2 seat assembly.
1. ADJUST FRONT LEG
HINT:
Perform the following procedure if the inner leg does not
lock.
P ...
Parking lights, low beams
and roadside parking lights
General information
If the driver's door is opened when the drive-ready
state is switched off, the exterior lighting is
automatically switched off.
Parking lights
General information
The parking lights can only be switched on in the
low speed range.
Switching on
Press the button on the light
switch ...
2Gr-fe emission control
SST
RECOMMENDED TOOLS
EQUIPMENT
SSM
2GR-FE INTAKE
EQUIPMENT
PREPARATION 2GR-FE EXHAUST
EQUIPMENT
...