what causes my Toyota Corolla E170 (2013-2019) headlights to flicker

Toyota Corolla E170 (2013-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

564 words

Problem Statement

Learn how to diagnose and fix flickering headlights on your 2013-2019 Toyota Corolla E170. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

Affected Component

Electrical

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components to prevent shocks.
•Allow the engine to cool before inspecting or working on the electrical system.

Symptoms

•Headlights intermittently flicker on and off
•Dimming or brightening of headlights when electrical accessories are used
•Possible dashboard warning lights illuminated
•Increased wear on headlight bulbs
•Electrical system components may show irregular function

Diagnostic Steps

1
Inspect the headlight bulbs for any signs of damage or improper installation.
2
Use an OBD-II scanner to check for any stored error codes related to the electrical system.
3
Examine the battery terminals and connections for corrosion or looseness.
4
Test the alternator output with a multimeter to ensure proper voltage is being supplied.
5
Inspect wiring harnesses for frayed wires or loose connections.
6
Check the headlight relay for proper operation.

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

•Multimeter
•OBD-II scanner
•Socket set
•Wire brush

Parts Required

•Headlight bulbs (if damaged)
•Headlight relay (if faulty)
•Alternator (if found defective)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Inspect the headlight bulbs for any signs of damage or improper installation.
2
Use an OBD-II scanner to check for any stored error codes related to the electrical system.
3
Examine the battery terminals and connections for corrosion or looseness.
4
Test the alternator output with a multimeter to ensure proper voltage is being supplied.
5
Inspect wiring harnesses for frayed wires or loose connections.
6
Check the headlight relay for proper operation.

Solution

1. Preparation

Gather tools including a multimeter, socket set, and OBD-II scanner.
Ensure the vehicle is parked on a level surface and the engine is off.

2. Inspect and Replace Headlight Bulbs

Open the hood and locate the headlight assembly.
Disconnect the electrical connector from the headlight bulb.
Remove the headlight bulb by twisting it counterclockwise.
Inspect the bulb for damage and replace it with a new one if necessary.
Reconnect the electrical connector and test the headlights.

3. Clean Battery Terminals and Connections

Disconnect the negative battery terminal using a socket set.
Inspect the terminal and cable for corrosion; clean with a wire brush if necessary.
Reconnect the negative terminal and ensure it is secure.

4. Test and Replace Alternator if Necessary

Start the engine and set the multimeter to measure DC voltage.
Connect the multimeter leads to the battery terminals (positive to positive, negative to negative).
Check the voltage reading; it should be between 13.8 to 14.5 volts.
If the reading is below this range, consider replacing the alternator.

5. Inspect and Repair Wiring Harness

Visually inspect the headlight wiring harness for any signs of wear or damage.
If any damaged wires are found, repair or replace them using electrical tape or heat-shrink tubing.
Ensure all connections are tight and secure.

6. Test and Replace Headlight Relay

Locate the headlight relay in the fuse box.
Remove the relay and test it according to the specifications in the vehicle’s service manual.
Replace with a new relay if it does not function correctly.