Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VKHY
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: LIGHTING (EXT): LIGHTING SYSTEM: Headlight (HI-BEAM) Circuit; 2016 - 2020 MY Sienna [12/2015 -        ]

Headlight (HI-BEAM) Circuit

DESCRIPTION

The main body ECU controls the high beam headlights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK HEADLIGHT

(a) Check the operation of low beam headlights.

OK:

Low beam headlights operate normally.

NG

GO TO 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 )
OK

2.

PERFORM ACTIVE TEST USING TECHSTREAM (HEAD LIGHT HI)

(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 / Active Test.

(e) Check that the relay operates.

Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Head Light HI

High beam headlight relay

ON/OFF

-

OK:

Relay operates. (High beam headlights illuminate.)

Result

Result

Proceed to

OK

A

NG (w/ Daytime running light system)

B

NG (w/o Daytime running light system)

C
A

REPLACE MAIN BODY ECU

C

GO TO STEP 6

B

3.

INSPECT RUNNING LIGHT RELAY

(a) Remove the running light relay from the engine room relay block assembly.

(b) Connect the positive (+) lead from the battery to terminal 6 (+B).

(c) Connect the negative (-) lead from the battery to terminal 4 (H).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1 (HLOR) - Body ground

Battery voltage not applied

Below 1 V

5 (HLOL) - Body ground

Below 1 V

1 (HLOR) - Body ground

Battery voltage applied to terminal 6 (+B) and 4 (H)

11 to 14 V

5 (HLOL) - Body ground

11 to 14 V

Text in Illustration

*a

Component without harness connected

(Running Light Relay)
NG

REPLACE RUNNING LIGHT RELAY

OK

4.

CHECK HARNESS AND CONNECTOR (RUNNING LIGHT RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

(a) Remove the running light relay from the engine room relay block assembly.

(b) Disconnect the 2F instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4 (H) - 2F-35

Always

Below 1 Ω

4 (H) or 2F-35 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2F-35 - 2I-22 (DIM)

Always

Below 1 Ω

2F-35 or 2I-22 (DIM) - Body ground

Always

10 kΩ or higher

Text in Illustration

*a

Component without harness connected

(Instrument Panel Junction Block Assembly)
OK

REPLACE MAIN BODY ECU

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

6.

INSPECT HEADLIGHT DIMMER RELAY

(a) Remove the DIM (headlight dimmer) relay from the engine room relay block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

Battery voltage not applied

10 kΩ or higher

Battery voltage applied between terminals 1 and 2

Below 1 Ω

Text in Illustration

*a

Component without harness connected

(Headlight Dimmer Relay)
NG

REPLACE HEADLIGHT DIMMER RELAY
OK

7.

CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

(a) Remove the headlight dimmer relay from the engine room relay block assembly.

(b) Disconnect the 2F instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2 - 2F-35

Always

Below 1 Ω

2 or 2F-35 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2F-35 - 2I-22 (DIM)

Always

Below 1 Ω

2F-35 or 2I-22 (DIM) - Body ground

Always

10 kΩ or higher

Text in Illustration

*a

Component without harness connected

(Instrument Panel Junction Block Assembly)
OK

REPLACE MAIN BODY ECU

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY