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

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

557 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 in Toyota Highlander (2014-2019). Step-by-step guide with symptoms, diagnostic steps, 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 components.
•Allow the engine to cool before opening the transmission or working under the vehicle.

Symptoms

•Engine RPM increases without acceleration
•Delayed engagement when shifting from park to drive/reverse
•Harsh or erratic shifting between gears
•Warning lights on the dashboard (e.g., check engine light)
•Unusual noises during gear changes (grinding or whining)
•Fluid leaks under the vehicle

Diagnostic Steps

1
Check the transmission fluid level and condition using the dipstick.
2
Scan the vehicle’s onboard computer for transmission-related error codes using an OBD-II scanner.
3
Inspect for any visible leaks around the transmission and fluid lines.
4
Test drive the vehicle to replicate the slipping issue while monitoring RPM and speed.
5
Check the transmission filter for clogs or contamination.
6
Inspect the transmission control module (TCM) 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

•OBD-II scanner
•Socket set
•Torque wrench
•Fluid pump
•Pan for fluid collection

Parts Required

•Transmission fluid (Toyota ATF WS)
•Transmission filter
•Transmission pan gasket

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Symptoms

•Engine RPM increases without acceleration

•Delayed engagement when shifting from park to drive/reverse

•Harsh or erratic shifting between gears

•Warning lights on the dashboard (e.g., check engine light)

•Unusual noises during gear changes (grinding or whining)

•Fluid leaks under the vehicle

Diagnostic Steps

1
Check the transmission fluid level and condition using the dipstick.
2
Scan the vehicle’s onboard computer for transmission-related error codes using an OBD-II scanner.
3
Inspect for any visible leaks around the transmission and fluid lines.
4
Test drive the vehicle to replicate the slipping issue while monitoring RPM and speed.
5
Check the transmission filter for clogs or contamination.
6
Inspect the transmission control module (TCM) for proper operation.

Solution

1. Preparation

Tools Required: OBD-II scanner, socket set, torque wrench, fluid pump, pan for fluid collection.
Ensure the vehicle is parked on a level surface and the engine is turned off.
Allow the vehicle to cool down before working on the transmission.

2. Check and Replace Transmission Fluid

Locate the Transmission Dipstick:
- Remove the dipstick and check the fluid level. It should be within the marked range.
Inspect Fluid Condition:
- The fluid should be a bright red color and should not have a burnt smell. If it’s dark or has a burnt odor, it needs to be replaced.
Drain Old Fluid:
- Place a pan under the transmission pan and remove the drain plug (if applicable) or the entire pan to drain the fluid.
Replace Filter:
- Remove the transmission pan completely, and replace the transmission filter. Ensure the old gasket is thoroughly cleaned from the pan and surface.
Install New Gasket and Pan:
- Install a new gasket on the transmission pan and torque the bolts to manufacturer specifications (usually around 10-15 ft-lbs).
Refill Transmission Fluid:
- Use a fluid pump to add new transmission fluid through the dipstick tube. Refer to the owner’s manual for the correct type of fluid (typically Toyota ATF WS).

3. Reset Transmission Control Module (if applicable)

Disconnect the vehicle’s battery for about 10 minutes to reset the TCM.
Reconnect the battery and allow the vehicle to relearn driving habits.