FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Why does my 2020 Toyota Highlander’s transmission slip? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/Why does my 2020 Toyota Highlander’s transmission slip?

Why does my 2020 Toyota Highlander’s transmission slip?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
3 min read
528 words

Problem Statement

Learn about the symptoms, diagnostic steps, and repair instructions for transmission slipping issues in the 2020 Toyota Highlander.

Affected Component
transmission

Symptoms

  • •Engine RPM increases without a corresponding increase in speed
  • •Harsh or delayed shifting between gears
  • •Warning lights such as the Check Engine light may illuminate
  • •Unusual noises or vibrations during gear changes
  • •Transmission fluid leaks under the vehicle

Diagnostic Steps

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

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

  • •Flashlight
  • •clean cloth
  • •transmission dipstick
  • •OBD-II scanner
  • •multimeter
  • •wiring diagrams
  • •socket set
  • •wrench
  • •funnel
  • •drain pan
  • •replacement sensors

Additional Information

Affected Component
transmission
Difficulty
medium
Severity
medium
Tools Required
11 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
Problem Overview: Transmission Slipping in 2020 Toyota Highlander

Symptoms:

  • Engine RPM increases without a corresponding increase in speed (engine revs freely).
  • Harsh or delayed shifting between gears.
  • Warning lights such as the Check Engine light may illuminate.
  • Unusual noises or vibrations during gear changes.
  • Transmission fluid leaks under the vehicle.
Repair Instructions

  1. Transmission Fluid Change:

    • Tools Required: Socket set, wrench, transmission fluid, funnel, drain pan.
    • If the fluid is dirty or burnt, perform a fluid change:
      • Raise the vehicle using jack stands.
      • Place a drain pan under the transmission pan.
      • Remove the drain plug or pan bolts and allow fluid to drain completely.
      • Replace the filter (if applicable) and gasket, then reassemble.
      • Fill the transmission with new fluid through the dipstick tube using a funnel.

  2. Transmission Control Module (TCM) Reset:

    • Tools Required: OBD-II scanner.
    • If DTCs indicate TCM issues, clear the codes using the OBD-II scanner and perform a reset.
    • Test drive the vehicle to see if issues persist.

  3. Inspect Transmission Mounts:

    • Tools Required: Wrench set.
    • Check the condition of the transmission mounts. If they are worn or damaged, replace them to prevent excessive movement that may cause shifting issues.

  4. Replace Faulty Sensors:

    • Tools Required: Socket set, replacement sensors.
    • If diagnostic codes indicate specific sensor failures (e.g., speed sensor), replace the affected sensors according to the manufacturer’s specifications.

  5. Professional Transmission Service:

    • Recommendation: If the issue persists after these steps, consult a professional technician who can perform a more in-depth diagnosis or transmission rebuild.
Conclusion

Transmission slipping can stem from various causes, including low or worn-out fluid, electrical issues, or faulty components. By following these diagnostic steps and necessary repairs, you can identify and often resolve the problem. If issues persist, professional assistance may be required for more complex repairs.