Toyota RAV4 (XA40) 2013-2018 Service Manual: Front fog light circuit
Description
The main body ecu controls the front fog light relay (marking: fr fog) when a
signal is received from
the headlight dimmer switch.
Wiring diagram

Inspection procedure
- Perform active test by intelligent tester
- Connect the intelligent tester (with can vim) to the
dlc3.
- Turn the ignition switch to the on position and press the
intelligent tester main switch on.
- Select the item below in the active test and then
check the relay operation.

Ok:
front fog light comes on.

- Check taillight
- Check that the taillight comes on when the light control
switch is on (tail).
Ok:
taillight comes on.

- Inspect fuse (fr fog)
- Remove the fr fog fuse from the instrument panel
junction block.
- Measure the resistance of the fuses.
Standard resistance:
below 1 

- Inspect fog light bulb

- Remove the fog light bulb.
- 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.

- Inspect front fog light relay (marking: fr fog)

- Remove the front fog light relay from the no. 6 Relay
block.
- Measure the resistance of the relay.
Standard resistance 

- Check wire harness (battery - main body ecu)

- Disconnect the e17 ecu connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 

- Check wire harness (front fog light relay - battery)

- Remove the front fog light relay from the no. 6 Relay
block.
- Measure the voltage of the relay block.
Standard voltage 

- Check wire harness (front fog light relay - front fog light and body
ground)

- Remove the front fog light relay from the no. 6 Relay
block.
- Disconnect the a11 and a28 front fog light connectors.
- Measure the resistance of the wire harness side
connectors.
Standard resistance 

Replace instrument panel junction block (main body ecu)
- Check wire harness (dimmer switch - main body ecu and body ground)

- Disconnect the e12 headlight dimmer switch connector.
- Disconnect the e17 main body ecu connector.
- Measure the resistance of the wire harness side
connectors.
Standard resistance 

- Inspect fog light switch

- Remove the headlight dimmer switch.
- Measure the resistance of the switch.
Standard resistance 

Repair or replace harness and connector (headlight dimmer switch - body
ground)
Description
The body ecu controls the headlight relay, no. 2 Daytime running light relay
(marking: drl no. 2) And
no. 4 Daytime running light relay (marking: drl no. 4).
Wiring diagram
I ...
Description
The turn signal flasher relay (marking: flsh) in the main body ecu turns on
when it receives signals
from the headlight dimmer switch integrated with the turn signal switch, causing
...
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Description
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the abs and traction
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Ecm power source circuit
Description
When the ignition switch is turned on, the battery voltage is applied to the
igsw of the ecm. The output
signal from the mrel terminal of the ecm causes a current to flow to the coil,
closing the contacts of the
integration relay (efi main relay) and supplying power to either term ...