Headlight Relay Circuit

DESCRIPTION

The main body ECU (driver side junction block assembly) controls the headlight relays.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1. PERFORM ACTIVE TEST 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 / Active Test.

(e) Check that the relays operate.

Main Body

Tester Display	Test Part	Control Range	Diagnostic Note
Headlight Relay	Headlight Relay	ON/OFF	-

OK:

Headlight relays operate. (Low beam headlights illuminate.)

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

1. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Remove the power distributor (engine room junction block assembly) from the engine room relay block (See page ).

(b) Connect a positive (+) lead from the battery to terminal 1A-1.

(c) Connect a negative (-) lead from the battery to terminal 1F-17.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
1D-1 - Battery negative	Always	11 to 14 V
1D-2 - Battery negative	Always	11 to 14 V

Text in Illustration

*1	Component without harness connected (Power Distributor (Engine Room Junction Block Assembly))

NG

REPLACE POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

OK

1. CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 1A power distributor (engine room junction block assembly) connector.

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

Standard Voltage:

Tester Connector	Condition	Specified Condition
1A-1 - Body ground	Always	11 to 14 V

Text in Illustration

*1	Front view of wire harness connector (to Power Distributor (Engine Room Junction Block Assembly))

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

1. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - MAIN BODY ECU)

(a) Disconnect the 1F power distributor (engine room junction block assembly) connector.

(b) Disconnect the 2G main body ECU (driver side junction block assembly) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1F-17 - 2G-35	Always	Below 1 Ω
1F-17 - Body ground	Always	10 kΩ or higher

Text in Illustration

*1	Front view of wire harness connector (to Power Distributor (Engine Room Junction Block Assembly))
*2	Front view of wire harness connector (to Main Body ECU (Driver Side Junction Block Assembly))

OK

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

NG

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE