how to fix the tail lights not working on Toyota Highlander Fourth Generation (2020-present)

Toyota Highlander Fourth Generation (2020-present)

Error Codes

1-2 hours

Time

medium

Difficulty

high

Severity

4 min read

616 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix tail lights not working on Toyota Highlander (2020-present). Step-by-step guide with symptoms, tools, and solutions.

Affected Component

Electrical

Estimated Time

1-2 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems to prevent shock.

Symptoms

•Tail lights do not illuminate when headlights are turned on
•Dashboard warning light for exterior lights is illuminated
•No lighting in the rear signal indicators
•Brake lights may also be non-functional
•Fuses related to tail lights are blowing frequently

Diagnostic Steps

1
Inspect the tail light bulbs for any signs of burning out or damage.
2
Check the tail light fuse in the fuse box for continuity.
3
Use an OBD-II scanner to check for any fault codes related to lighting systems.
4
Verify the wiring harness for any signs of wear, corrosion, or disconnection.
5
Test the tail light switch functionality using a multimeter.
6
Check the grounding point for the tail lights to ensure proper grounding.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•Screwdriver set
•Fuse puller or pliers
•Multimeter
•Wire strippers

Parts Required

•Replacement tail light bulbs
•Replacement tail light fuse (if needed)
•New tail light switch (if needed)

Related Faults

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Diagnostic Steps

1
Inspect the tail light bulbs for any signs of burning out or damage.
2
Check the tail light fuse in the fuse box for continuity.
3
Use an OBD-II scanner to check for any fault codes related to lighting systems.
4
Verify the wiring harness for any signs of wear, corrosion, or disconnection.
5
Test the tail light switch functionality using a multimeter.
6
Check the grounding point for the tail lights to ensure proper grounding.

Solution

1. Preparation

Gather all necessary tools and parts.
Disconnect the battery to prevent electrical shock.
Ensure the vehicle is parked on a flat surface with the ignition off.

2. Inspect and Replace Tail Light Bulbs

Tools Required: Screwdriver set, replacement bulbs
Remove the tail light assembly by unscrewing the screws or bolts securing it.
Pull the assembly away from the vehicle body.
Twist the bulb socket counterclockwise to remove the bulb.
Inspect the bulb; if it is burnt out, replace it with a new bulb of the same type.
Reinstall the bulb socket and tail light assembly, securing it with screws or bolts.

3. Check and Replace the Tail Light Fuse

Tools Required: Fuse puller or pliers
Locate the fuse box, typically found under the dashboard or in the engine compartment.
Identify the tail light fuse using the diagram on the fuse box cover.
Remove the fuse and inspect it for continuity.
If the fuse is blown, replace it with a new fuse of the same amperage rating.

4. Repair Wiring and Grounding

Tools Required: Wire strippers, electrical tape, multimeter
Inspect the wiring harness leading to the tail lights for any visible damage.
If damaged, use wire strippers to remove insulation from the damaged wire and splice in a new section of wire.
Ensure all connections are solid and secure; use electrical tape to insulate.
Locate the grounding point for the tail lights and clean it to ensure a solid connection. Tighten any loose connections.

5. Test the Tail Light Switch

Tools Required: Multimeter
Locate the tail light switch, usually mounted on the steering column.
Disconnect the switch connector and use a multimeter to test for continuity when the switch is activated.
If the switch shows no continuity, replace it with a new switch.