Toyota RAV4 Service Manual: Headlight relay circuit

Description

When the light control switch, located on the headlight dimmer switch, is turned to the head position, the head relay illuminates the headlights.

Wiring diagram

Inspection procedure

1. Perform active test by intelligent tester (headlight)

1. Connect the intelligent tester (with can vim) to the dlc3.
2. Turn the ignition switch on and press the intelligent tester main switch on.
3. Select the item below in the active test and then check the relay operation.

Ok: headlight comes on

2. Inspect fuse (head ll, head rl)

1. Remove the head ll fuse and head rl fuse from the engine room no. 2 Relay block.
2. Measure the resistance of the fuses.

Standard resistance: below 1

3. Inspect headlight relay (marking: head)

1. Remove the headlight relay from the engine room no. 2 Relay block.
2. Measure the resistance of the relay.

Standard resistance

4. Inspect bulb (headlight bulb)

1. Remove the headlight bulbs (low).
2. Connect the positive (+) lead from the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the bulb illuminates.

Ok: bulb illuminates.

5. Check wire harness (main body ecu - battery)

1. Disconnect the e15 main body ecu connector.
2. Measure the voltage of the wire harness side connector.

Standard voltage 

6. Check instrument panel junction block (main body ecu)

1. Measure the voltage of the main body ecu.

Standard voltage

Repair or replace harness and connector (head relay - headlight bulb and body ground)

7. Check wire harness (headlight dimmer switch - main body ecu)

1. Disconnect the e17 main body ecu connector.
2. Disconnect the e12 headlight dimmer switch connector.
3. Measure the resistance of the wire harness side connectors.

Standard resistance

1. Inspect headlight dimmer switch

1. Disconnect the e12 headlight dimmer switch.
2. Measure the resistance of the switch.

Standard resistance

Repair or replace harness and connector (headlight dimmer switch - body ground)