Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VKHI
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: LIGHTING (EXT): LIGHTING SYSTEM: Light Control Switch Circuit; 2016 - 2020 MY Sienna [12/2015 -        ]

Light Control Switch Circuit

DESCRIPTION

The main body ECU receives the following switch information:

  • Light control switch position DRL-OFF*1, off*2, tail, head, DRL*3 or AUTO*4
  • Dimmer switch position high, low or high flash (pass)
  • Fog light switch position on or off
    • *1: w/ DRL OFF switch
    • *2: w/o DRL OFF switch
    • *3: w/ DRL switch
    • *4: w/ Automatic Light Control System

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

(e) Read the display on the Techstream.

Main Body

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Dimmer SW

Dimmer switch high position signal/ON or OFF

ON: Dimmer switch in high or high flash (pass) position

OFF: Dimmer switch in low position

-

Passing Light SW

Dimmer switch high flash (pass) position signal/ON or OFF

ON: Dimmer switch in high flash (pass) position

OFF: Dimmer switch not in high flash (pass) position

-

Front Fog Light SW

Front fog light switch signal/ON or OFF

ON: Front fog light switch on

OFF: Front fog light switch off

-

Auto Light SW

Light control switch AUTO*1 or DRL*2 position signal/ON or OFF

ON: Light control switch in AUTO*1 or DRL*2 position

OFF: Light control switch not in AUTO*1 or DRL*2 position

-

Head Light SW (Head)

Light control switch head position signal/ON or OFF

ON: Light control switch in head position

OFF: Light control switch not in head position

-

Head Light SW (Tail)

Light control switch tail position signal/ON or OFF

ON: Light control switch in tail or head position

OFF: Light control switch in neither tail nor head position

-

  • *1: w/ Automatic Light Control System
  • *2: w/ DRL Switch

OK:

Normal conditions listed above are displayed.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

(See page 2016 MY Sienna [12/2015 - 08/2016]; LIGHTING (EXT): LIGHTING SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; LIGHTING (EXT): LIGHTING SYSTEM: PROBLEM SYMPTOMS TABLE 2018 - 2020 MY Sienna [11/2017 -        ]; LIGHTING (EXT): LIGHTING SYSTEM: PROBLEM SYMPTOMS TABLE )

NG

2.

INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

HINT:

Inspect the items that did not change as a result of monitoring the Data List.

(a) Remove the headlight dimmer switch assembly (See page 2016 - 2020 MY Sienna [12/2015 -        ]; LIGHTING (EXT): HEADLIGHT DIMMER SWITCH: REMOVAL ).

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

Standard Resistance:

Light Control Switch

Tester Connection

Switch Condition

Specified Condition

12 (EL) - 18 (T)

OFF

10 kΩ or higher

18 (T) - 19 (A)

OFF

10 kΩ or higher

19 (A) - 20 (H)

OFF

10 kΩ or higher

12 (EL) - 18 (T)

TAIL

Below 1 Ω

12 (EL) - 18 (T)

HEAD

Below 1 Ω

18 (T) - 20 (H)

HEAD

Below 1 Ω

12 (EL) - 19 (A)

AUTO

Below 1 Ω

Dimmer Switch

Tester Connection

Switch Condition

Specified Condition

11 (HU) - 12 (EL)

LOW

10 kΩ or higher

11 (HU) - 12 (EL)

HIGH

Below 1 Ω

12 (EL) - 17 (HF)

HIGH FLASH

Below 1 Ω

Fog Light Switch

Tester Connection

Switch Condition

Specified Condition

3 (LFG) - 4 (BFG)

OFF

10 kΩ or higher

3 (LFG) - 4 (BFG)

ON

Below 1 Ω

Text in Illustration

*a

Component without harness connected:

(Headlight Dimmer Switch Assembly)

NG

REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY

OK

3.

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - HEADLIGHT DIMMER SWITCH ASSEMBLY)

(a) Disconnect the D147 headlight dimmer switch assembly connector.

(b) Disconnect the D13 main body ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D147-4 (BFG) - D13-27 (FFOG)

Always

Below 1 Ω

D147-11 (HU) - D13-5 (HU)

Always

Below 1 Ω

D147-17 (HF) - D13-8 (HF)

Always

Below 1 Ω

D147-18 (T) - D13-30 (TAIL)

Always

Below 1 Ω

D147-19 (A) - D13-28 (A)

Always

Below 1 Ω

D147-20 (H) - D13-29 (HEAD)

Always

Below 1 Ω

D147-3 (LFG) - Body ground

Always

Below 1 Ω

D147-4 (BFG) or D13-27 (FFOG)- Body ground

Always

10 kΩ or higher

D147-11 (HU) or D13-5 (HU)- Body ground

Always

10 kΩ or higher

D147-17 (HF) or D13-8 (HF)- Body ground

Always

10 kΩ or higher

D147-18 (T) or D13-30 (TAIL)- Body ground

Always

10 kΩ or higher

D147-19 (A) or D13-28 (A)- Body ground

Always

10 kΩ or higher

D147-20 (H) or D13-29 (HEAD)- Body ground

Always

10 kΩ or higher

D147-12 (EL) - Body ground

Always

Below 1 Ω

OK

REPLACE MAIN BODY ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR