Headlight Signal Circuit: Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR

Disconnect connector 1G from the engine room junction block.

Fig 1: Identifying Terminals Of Combination SW ECU Connector Terminals
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Disconnect the connector from the combination SW ECU.

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

Fig 2: Identifying 1G Connector Terminals

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Standard resistance

Tester Connection	Condition	Specified Condition
1G-6 - D13-4	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

INSPECT WINDSHIELD WIPER SWITCH ASSEMBLY (COMBINATION SWITCH ECU)

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

Fig 3: Identifying Terminals Of Combination SW ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance

Tester Connection	Condition	Specified Condition
D13-4 - D13-5	Light control switch in the HEAD position	Below 1 Ω
D13-4 - D13-5	Light control switch in except the HEAD position	10 kΩ or higher

NG → REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY

OK: Go to next step

CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH ECU - BODY GROUND)

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

Fig 4: Identifying Terminals Of Combination SW ECU Connector Terminals

Standard resistance

Tester Connection	Condition	Specified Condition
D13-5 - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → PROCEED TO PROBLEM SYMPTOMS TABLE NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE