my Toyota Highlander transmission slips when shifting gears what could be wrong

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

541 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 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

•Transmission slips during gear shifts
•Unusual engine revving without corresponding vehicle acceleration
•Delayed engagement when shifting from Park to Drive
•Warning lights illuminated on the dashboard (e.g., check engine light)
•Fluid leaks under the vehicle
•Burning smell from the transmission area

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify potential transmission-related issues.
2
Check the transmission fluid level and condition (color and smell).
3
Inspect the transmission fluid for leaks at the seals and pan.
4
Examine the transmission filter for clogs or damage.
5
Test the transmission control module (TCM) for proper function.
6
Verify the operation of the throttle position sensor (TPS) and its effect on shifting.

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 pump
•Catch pan
•Socket set
•Torque wrench
•Multimeter

Parts Required

•Transmission fluid
•Transmission filter
•Gasket for transmission pan
•Seals (if needed)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Symptoms

•Transmission slips during gear shifts

•Unusual engine revving without corresponding vehicle acceleration

•Delayed engagement when shifting from Park to Drive

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

•Fluid leaks under the vehicle

•Burning smell from the transmission area

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify potential transmission-related issues.
2
Check the transmission fluid level and condition (color and smell).
3
Inspect the transmission fluid for leaks at the seals and pan.
4
Examine the transmission filter for clogs or damage.
5
Test the transmission control module (TCM) for proper function.
6
Verify the operation of the throttle position sensor (TPS) and its effect on shifting.

Solution

1. Preparation

Gather necessary tools and materials.
Ensure the vehicle is parked on a level surface and the engine is off.
Disconnect the battery to prevent electrical issues during repairs.

2. Check and Replace Transmission Fluid

Tools Required: Transmission fluid pump, funnel, catch pan, socket set, torque wrench.
Remove the transmission pan using a socket set, ensuring to catch any fluid in a pan.
Inspect the fluid condition; it should be red and not burnt. If it's dark or smells burnt, replace it.
Replace the transmission filter if necessary.
Reinstall the pan with a new gasket, torque bolts to manufacturer specifications.
Refill the transmission with the appropriate type and amount of fluid.

3. Inspect and Repair Transmission Components

Tools Required: Torque wrench, various socket sizes, screwdriver set.
Inspect the transmission seals and gaskets for leaks; replace if damaged.
Check the transmission control module (TCM) wiring and connectors for corrosion or damage; repair or replace as necessary.
Test the throttle position sensor (TPS) using a multimeter; replace if readings are outside specifications.

4. Reassemble and Test

Reconnect the battery and ensure all components are securely fastened.
Start the vehicle and allow it to reach operating temperature.
Test drive the vehicle to check for proper shifting and slipping issues.