Toyota Highlander Third Generation (2014-2019) transmission slipping when accelerating how to fix

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

584 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 transmission slipping issues in the 2014-2019 Toyota Highlander. Step-by-step guide with diagnostic procedures and repair instructions.

Affected Component

Transmission

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems.
•Allow the engine to cool before working on the transmission to avoid burns.

Symptoms

•Check engine light illuminated
•Noticeable increase in engine RPM without corresponding vehicle acceleration
•Delayed or harsh shifting between gears
•Fluid leakage under the vehicle
•Unusual whining or grinding noises during acceleration

Diagnostic Steps

1
Scan the vehicle's onboard diagnostics (OBD-II) system for any error codes.
2
Check the transmission fluid level and condition with the engine running and transmission in park.
3
Inspect the transmission fluid for contamination or burning smell.
4
Examine the transmission filter for clogging or restrictions.
5
Test the operation of the transmission shift solenoids using a multimeter.
6
Look for any visible signs of wear or damage on the transmission components.

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
•Socket set
•Torque wrench
•Fluid catch container
•Multimeter

Parts Required

•Toyota WS ATF transmission fluid
•Transmission filter
•Transmission pan gasket
•Shift solenoids (if needed)

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Diagnostic Steps

1
Scan the vehicle's onboard diagnostics (OBD-II) system for any error codes.
2
Check the transmission fluid level and condition with the engine running and transmission in park.
3
Inspect the transmission fluid for contamination or burning smell.
4
Examine the transmission filter for clogging or restrictions.
5
Test the operation of the transmission shift solenoids using a multimeter.
6
Look for any visible signs of wear or damage on the transmission components.

Solution

1. Preparation

Ensure the vehicle is parked on a level surface and the engine is off.
Gather necessary tools and parts.
Disconnect the battery to ensure safety while working on electrical components.

2. Check and Replace Transmission Fluid

Sub-steps:
1. Remove the transmission dipstick and wipe it clean.
2. Insert it back and check the fluid level; add fluid if low.
3. If the fluid is discolored or has a burnt odor, proceed to drain and replace it.
4. Use a wrench to remove the transmission drain plug and allow fluid to drain completely into a suitable container.
5. Replace the drain plug and tighten it to the manufacturer's torque specification (usually around 30 ft-lbs).
6. Refill the transmission with the correct type of fluid (Toyota WS ATF) through the dipstick tube until it reaches the proper level.

3. Replace Transmission Filter

Sub-steps:
1. Remove the transmission pan using a socket set, taking care to catch any remaining fluid.
2. Remove the old transmission filter from the valve body.
3. Clean the transmission pan thoroughly and inspect for metal shavings or debris.
4. Install the new transmission filter by aligning it correctly with the mounting points.
5. Replace the transmission pan with a new gasket and torque the bolts to specifications (usually around 8 ft-lbs).

4. Inspect and Replace Shift Solenoids (if necessary)

Sub-steps:
1. Locate the transmission shift solenoids (usually found on the valve body).
2. Disconnect the electrical connectors from the solenoids.
3. Remove the solenoids using a socket set.
4. Install the new solenoids, ensuring they are securely connected.
5. Reconnect the battery and clear any error codes from the OBD-II system.