Toyota CH-R Service Manual: Low Beam Headlight Circuit

Toyota CH-R Service Manual / Lighting (ext) / Lighting System / Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the low beam headlights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses and bulbs for circuits related to this system before performing the following procedure.
  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.*1

    Click here

    • *1: w/ Smart Key System

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT RELAY)

(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.

Body Electrical > Main Body > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Headlight Relay

Low beam headlights

ON or OFF

-
Body Electrical > Main Body > Active Test

Tester Display

Headlight Relay

OK:

Headlight relay operates. (Low beam headlights illuminate.)

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

INSPECT NO. 1 INTEGRATION RELAY (H-LP LH RELAY, H-LP RH RELAY)

(a) Remove the No. 1 integration relay from the No. 1 engine room relay block.

Click here

(b) Inspect the No. 1 integration relay.

Click here

OK:

No. 1 integration relay is normal.

NG

REPLACE NO. 1 INTEGRATION RELAY

OK

3.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BATTERY)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1A-5 - Body ground

Always

11 to 14 V

1B-8 - Body ground

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY LH AND HEADLIGHT ASSEMBLY RH AND BODY GROUND)

(a) Disconnect the A9 headlight assembly LH connector.

(b) Disconnect the A28 headlight assembly RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1B-1 - A9-2 (LO)

Always

Below 1 Ω

1A-12 - A28-2 (LO)

Always

Below 1 Ω

A9-1 (E) - Body ground

Always

Below 1 Ω

A28-1 (E) - Body ground

Always

Below 1 Ω

1B-1 - Body ground

Always

10 kΩ or higher

1A-12 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

(a) Disconnect the 3F instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1A-11 - 3F-31

Always

Below 1 Ω

1B-2 - 3F-31

Always

Below 1 Ω

1A-11 or 3F-31 - Body ground

Always

10 kΩ or higher

1B-2 or 3F-31 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

Click here

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

*a

Component without harness connected

(Instrument Panel Junction Block Assembly)

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

3F-31 - MB-15 (HRLY)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Power Source Circuit
    DESCRIPTION When the ignition switch is ON or the operation conditions of the headlights are met, the main body ECU (multiplex network body ECU) supplies power to the headlight ECU sub-assemblies ...

    High Beam Headlight Circuit
    DESCRIPTION The main body ECU (multiplex network body ECU) controls the high beam headlights. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuse for circuits related to thi ...

    Other materials:

    Toyota CH-R Service Manual > Lighting (int): Vanity Light Bulb
    Replacement REPLACEMENT CAUTION / NOTICE / HINT HINT: Use the same procedure for both the LH and RH sides. The procedure described below is for the LH side. PROCEDURE 1. REMOVE VANITY LIGHT ASSEMBLY Click here 2. REMOVE VANITY LIGHT BULB (a) Remove the vanity light bul ...

    Toyota CH-R Service Manual > Windshield Deicer System: How To Proceed With Troubleshooting
    CAUTION / NOTICE / HINT HINT: Use the following procedure to troubleshoot the windshield deicer system. *: Use the Techstream. PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP NEXT ...

    Toyota C-HR (AX20) 2023-2025 Owner's Manual

    Toyota CH-R Owners Manual

    Toyota CH-R Service Manual

    © 2017-2025 Copyright www.tochr.net
    0.0107