Toyota RAV4 (XA40) 2013-2018 Service Manual: Taillight relay circuit
Description
When the light control switch, located on the headlight dimmer switch, is
turned to the tail position, the
taillight relay (marking: t-lp) turns on to illuminate the front side marker
lights, rear taillights, side marker
lights and license plate light.
Wiring diagram


Inspection procedure
- Check whether lights illuminate
- Check whether the following lights illuminate: front side
marker lights, rear taillights, side marker lights and
license plate light.


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

- Check wire harness (battery - instrument panel junction block)

- Disconnect the ig instrument panel junction block
connector.
- Measure the voltage of the wire harness side connector.
Standard voltage

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

- Disconnect the e15 main body ecu connector.
- Disconnect the e12 headlight dimmer switch connector.
- Measure the resistance of the wire harness side
connectors.
Standard resistance 

- Check wire harness (battery - headlight dimmer switch)

- Connect the e15 main body ecu connector.
- Disconnect the e12 headlight dimmer switch connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 

- Check wire harness (headlight dimmer switch - body ground)

- Disconnect the e12 headlight dimmer switch connector.
- Measure the resistance of the wire harness side
connector.
Standard resistance 

- Inspect headlight dimmer switch

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

Replace instrument panel junction block
- Check instrument panel junction block (taillight relay)

- Disconnect the ib instrument panel junction block
connector.
- Measure the voltage of the junction block.
Standard voltage 

- Check wire harness (taillight relay - front side
marker light and body ground)

- Disconnect the a12 and a24 front side marker light
connectors.
- Measure the voltage and resistance of the wire harness
side connectors.
Standard resistance 
standard resistance 

Replace bulb
- Check wire harness (main body ecu - rear combination light)
- Disconnect the k12 and k14 rear combination light
connectors.
- Measure the voltage and resistance of the wire harness
side connectors.
Standard voltage
Standard resistance 

Replace rear combination light
- Check wire harness (main body ecu - license plate light and body
ground)

- Disconnect the q6 license plate light connector.
- Measure the voltage and resistance of the wire harness
side connector.
Standard voltage
Standard resistance 

Replace bulb
- Check wire harness (main body ecu - rear combination light)

- Disconnect the k12 and k14 rear combination light
connectors.
- Measure the voltage and resistance of the wire harness
side connectors.
Standard voltage
Standard resistance 

Replace bulb
Description
The main body ecu receives information regarding the door courtesy switch and
door lock position
switch, and turns on the room light.
Wiring diagram
Inspection procedure
Perf ...
Components
Removal
Hint:
Use the same procedures for the rh and lh sides.
The procedures listed below are for the lh side.
Disconnect cable from negative battery
terminal
Rem ...
Other materials:
Diagnostic trouble code chart
Hint:
If no abnormality is found when inspecting parts, check the
skid control ecu and check for poor contact at the ground
points.
If a dtc is displayed during the dtc check, check the
circuit for the dtc listed in the table below. For details of
each dtc, refer to the page indicated. ...
Dtc check / clear
Notice:
When the diagnosis system is changed from normal
mode to check mode or vice versa, all dtcs and freeze
frame data recorded in normal mode are erased. Before
changing modes, always check and make a note of any
dtcs and freeze frame data.
Hint:
Dtcs which are stored in the ecm can be ...
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "suspected area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Re ...