FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
What should I do if my 2023 Toyota Highlander won't start? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What should I do if my 2023 Toyota Highlander won't start?

What should I do if my 2023 Toyota Highlander won't start?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
749 words

Problem Statement

Learn how to diagnose and fix starting issues with your 2023 Toyota Highlander, including symptoms, diagnostic steps, and tools required.

Affected Component
starting system

Symptoms

  • •No Crank
  • •Clicking Sound
  • •Dashboard Lights
  • •Battery Warning Light
  • •Engine Turns Over Slowly

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

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

  • •Digital Multimeter
  • •Jumper Cables
  • •Second Vehicle
  • •Fuse Puller or Needle Nose Pliers
  • •Socket Set
  • •Wrench
  • •Relay Tester or Multimeter
  • •OBD-II Scanner

Additional Information

Affected Component
starting system
Difficulty
medium
Severity
medium
Tools Required
8 items

Related Faults

Loading...

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation

If your 2023 Toyota Highlander won't start, it can be due to a variety of issues ranging from a dead battery to more complex mechanical problems. Below is a detailed guide to diagnosing and potentially fixing the issue.

Step 1: Check Battery Condition
  1. Visual Inspection: Inspect battery terminals for corrosion or loose connections.
  2. Multimeter Test: Use a digital multimeter to check the battery voltage.
    • Tools Required: Digital Multimeter
    • Procedure:
      • Set the multimeter to the DC voltage setting.
      • Place the positive probe on the positive terminal and the negative probe on the negative terminal.
      • A healthy battery should read around 12.6 volts or higher.
Step 2: Jump Start the Vehicle

If the battery voltage is low (below 12.4 volts):

  1. Jump Start: Attempt to jump-start the vehicle using jumper cables and another vehicle.
    • Tools Required: Jumper Cables, Second Vehicle
    • Procedure:
      • Connect the positive cable to the dead battery’s positive terminal and the other end to the working battery’s positive terminal.
      • Connect the negative cable to the working battery’s negative terminal, then clamp the other end to a metal ground on the non-starting vehicle.
      • Start the working vehicle and let it run for a few minutes, then attempt to start your Highlander.
Step 3: Check Fuses
  1. Fuse Box Inspection: Locate the fuse box and check for blown fuses related to the ignition and starter system.
    • Tools Required: Fuse Puller or Needle Nose Pliers
    • Procedure:
      • Remove the fuse box cover (consult your owner’s manual for location).
      • Inspect fuses related to the ignition (typically labeled in the cover).
      • Replace any blown fuses with the same amperage rating.
Step 4: Inspect Starter Motor

If the battery is good and fuses are intact:

  1. Starter Test: Check if the starter motor is functioning.
    • Tools Required: Socket Set, Wrench
    • Procedure:
      • Locate the starter motor (usually near the transmission).
      • Check the wiring and connections for looseness or corrosion.
      • Use a multimeter to test the starter’s power supply while someone attempts to start the engine.
      • If there’s power but the starter doesn’t engage, it may need to be replaced.
Step 5: Check Ignition System
  1. Ignition Relay Test: If the starter is working, check the ignition relay.
    • Tools Required: Relay Tester or Multimeter
    • Procedure:
      • Locate the ignition relay in the fuse box.
      • Swap it with a similar relay (if available) to see if the issue persists.
      • If the relay is faulty, replace it.
Step 6: Scan for Diagnostic Trouble Codes (DTC)
  1. OBD-II Scanner: Use a scanner to check for any stored trouble codes.
    • Tools Required: OBD-II Scanner
    • Procedure:
      • Connect the OBD-II scanner to the vehicle’s diagnostic port.
      • Turn the ignition to the “ON” position without starting the engine.
      • Follow the scanner instructions to retrieve codes.
      • Investigate any codes related to the starting system.
Repair Instructions
If Battery is Faulty:
  1. Replace the Battery: If the battery is weak or bad, replace it with a new one.
    • Procedure:
      • Disconnect negative terminal first, then positive.
      • Remove the battery hold-downs.
      • Replace with a new battery and connect terminals in reverse order.
If Starter is Faulty:
  1. Replace Starter: If the starter is defective, replace it.
    • Procedure:
      • Disconnect battery.
      • Remove starter wiring harness and bolts securing the starter.
      • Install new starter and reconnect all components.
If Ignition Relay is Faulty:
  1. Replace Ignition Relay: If the relay is defective.
    • Procedure:
      • Remove the faulty relay and replace it with a new one.
If DTC indicates a specific issue:
  1. Address the Specific Code: Follow repair manuals specific to the DTC for guidance on repairs.
Conclusion

If after following these steps your 2023 Toyota Highlander still does not start, it may be necessary to consult a professional technician or take the vehicle to a Toyota service center for further diagnosis.