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What are the symptoms of a failing transmission in the 2020 Toyota Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the symptoms of a failing transmission in the 2020 Toyota Highlander?

What are the symptoms of a failing transmission in the 2020 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
high
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
760 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 about the common symptoms of a failing transmission in the 2020 Toyota Highlander, including unusual noises, slipping gears, delayed engagement, and more.

Affected Component
transmission

Symptoms

  • •Grinding, whining, or clunking sounds when shifting gears
  • •Noise when the vehicle is in neutral
  • •The engine revs without a corresponding increase in vehicle speed
  • •The vehicle unexpectedly shifts out of gear
  • •A noticeable delay between shifting from park to drive or reverse
  • •You may feel a sudden jolt when the gear engages
  • •Transmission warning light illuminated on the dashboard
  • •Check Engine light may also be illuminated
  • •Puddles of red or brown fluid under the vehicle
  • •Low transmission fluid levels can lead to overheating and failure
  • •The transmission may overheat, indicated by a hot transmission fluid smell
  • •Rough or harsh shifting between gears
  • •Unpredictable behavior when accelerating or decelerating

Diagnostic Steps

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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

  • •OBD-II Scanner
  • •Transmission Fluid Dipstick (if applicable)
  • •Transmission Fluid (as needed for refills)
  • •Funnel for fluid changes
  • •Drain Pan
  • •Socket Set and Wrenches
  • •Torque Wrench
  • •Screwdrivers
  • •Safety Glasses and Gloves

Additional Information

Affected Component
transmission
Difficulty
medium
Severity
high
Tools Required
9 items

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Back to Generation

Symptoms of a Failing Transmission in the 2020 Toyota Highlander (Fourth Generation)

The transmission is a critical component of any vehicle, and issues can lead to significant performance problems. For the 2020 Toyota Highlander, here are common symptoms of a failing transmission:

1. Unusual Noises
2. Slipping Gears
3. Delayed Engagement
4. Warning Lights
5. Fluid Leaks
6. Overheating
7. Erratic Shifting
Tools Required for Diagnosis and Repair
  • OBD-II Scanner
  • Transmission Fluid Dipstick (if applicable)
  • Transmission Fluid (as needed for refills)
  • Funnel for fluid changes
  • Drain Pan
  • Socket Set and Wrenches
  • Torque Wrench
  • Screwdrivers
  • Safety Glasses and Gloves

Diagnostic and Repair Steps

Step 1: Initial Inspection
  1. Visual Check: Inspect the transmission for any visible leaks or damage.
  2. Fluid Level Check: Use the dipstick to check fluid levels. If low, top off with the correct transmission fluid as specified in the owner’s manual.
Step 2: Scanning for Codes
  1. Connect OBD-II Scanner: Plug in the scanner to the OBD-II port.
  2. Read Codes: Identify any transmission-related trouble codes.
  3. Document Codes: Make a note of the codes for further research.
Step 3: Test Drive
  1. Conduct a Test Drive: Drive the vehicle under various conditions (stop-and-go, highway speeds).
  2. Observe Symptoms: Pay attention to any slipping, delayed engagement, or erratic shifting.
Step 4: Fluid Condition Check
  1. Check Fluid Condition: Inspect the transmission fluid for discoloration or burnt smell.
  2. Replace Fluid: If the fluid is contaminated, perform a transmission fluid change.
Fluid Change Instructions:
  1. Lift the Vehicle: Use a jack and jack stands for safety.
  2. Drain Fluid: Place a drain pan under the transmission pan and remove the drain plug or pan bolts.
  3. Replace Filter: If applicable, replace the transmission filter.
  4. Reinstall Pan: Torque the pan bolts to manufacturer specifications.
  5. Refill Fluid: Use a funnel to refill with new transmission fluid through the dipstick tube.
Step 5: Addressing Mechanical Issues
  1. Inspect Transmission Mounts: Ensure mounts are intact and not causing misalignment.
  2. Check Linkage: Inspect the shift linkage for wear or damage.
  3. Transmission Rebuild or Replacement: If internal components are suspected to be failing, consider consulting a professional for a rebuild or replacement.
Step 6: Recheck
  1. Re-test: After any repairs, re-test the vehicle to ensure symptoms are resolved.
  2. Monitor Performance: Continue to monitor the transmission performance over time.

Conclusion

If after following these steps the problem persists or if you are uncomfortable performing any of the repairs, it is advisable to seek assistance from a certified automotive technician or a Toyota dealership. Timely intervention can prevent further damage and ensure the longevity of your transmission.