Toyota RAV4 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

1. Check whether lights illuminate

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

2. Inspect fuse (tail)

1. Remove the tail fuse from the instrument panel junction block.
2. Measure the resistance of the fuse.

Standard resistance: below 1

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

1. Disconnect the ig instrument panel junction block connector.
2. Measure the voltage of the wire harness side connector.

Standard voltage

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

1. Disconnect the e15 main body ecu connector.
2. Disconnect the e12 headlight dimmer switch connector.
3. Measure the resistance of the wire harness side connectors.

Standard resistance

5. Check wire harness (battery - headlight dimmer switch)

1. Connect the e15 main body ecu connector.
2. Disconnect the e12 headlight dimmer switch connector.
3. Measure the voltage of the wire harness side connector.

Standard voltage

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

1. Disconnect the e12 headlight dimmer switch connector.
2. Measure the resistance of the wire harness side connector.

Standard resistance

7. Inspect headlight dimmer switch

1. Remove the headlight dimmer switch.
2. Measure the resistance of the switch.

Standard resistance

Replace instrument panel junction block

8. Check instrument panel junction block (taillight relay)

1. Disconnect the ib instrument panel junction block connector.
2. Measure the voltage of the junction block.

Standard voltage

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

1. Disconnect the a12 and a24 front side marker light connectors.
2. Measure the voltage and resistance of the wire harness side connectors.

Standard resistance

standard resistance

Replace bulb

10. Check wire harness (main body ecu - rear combination light)

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

Standard voltage

Standard resistance

Replace rear combination light

11. Check wire harness (main body ecu - license plate light and body ground)

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

Standard voltage

Standard resistance

Replace bulb

12. Check wire harness (main body ecu - rear combination light)

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

Standard voltage

Standard resistance

Replace bulb