2021 Toyota Highlander AWD System Problems – Causes, Fix and Repair Guide

Problem Overview

AWD technology found in the 2021 Toyota Highlander is programmed to automatically balance the flow of energy between the front and rear wheels for improved control. Any problem with this technology would result in poor traction, illumination of lights, and even failure of the vehicle to shift to all wheel drive. Some vehicles end up being front-wheel driven due to such problems.

The information provided here is sourced from the official Workshop Manual used by technicians and dealerships to diagnose and repair Toyota AWD systems. It’s an essential guide for any owner – Click here to get the Toyota Highlander Service and Repair Manual.

Engines Covered

2.4L Turbocharged 4-Cylinder
2.5L Hybrid 4-Cylinder
3.5L V6 (older models)

Common Symptoms

These are some of the most prevalent symptoms: loss of grip while driving in slippery situations, AWD light coming on in the dashboard, abnormal vibration while accelerating, as well as uneven wheel power distribution. It is possible for the driver to hear some clicking and/or grinding sounds when making turns at a low speed and/or when accelerating.

A more serious problem is when the car goes into FWD-only drive mode.

What Causes 2021 Toyota Highlander AWD System Problems

These causes are usually low or poor quality of the differential fluid, old parts of the transfer case, malfunctioning wheel speed sensors, or damaged driveshafts or CV joints. It is also possible that software problems inside the all-wheel-drive module may interfere with the performance of the system.

In order to find the cause of the problem, use the OBD2 scanner for traction control codes of the vehicle. Look at the fluid in the rear differential and transfer case, then check the condition of the wheel speed sensors for any damages or dirt. Finally, take the car on a test ride.

How to Fix 2021 Toyota Highlander AWD System Problems

  • Depending on the issue, you may need to
  • Replace differential and transfer case fluid
  • Replace faulty wheel speed sensors
  • Repair or replace CV joints or driveshaft components
  • Update AWD control software
  • Repair wiring or connectors in the traction system

Parts You May Need and Where to Buy Them

  • Differential fluid
  • Transfer case fluid
  • Wheel speed sensors
  • Driveshaft components
  • CV joints
  • AWD control module (in rare cases)

If you’re planning to buy one, be sure to check out our complete buyer’s guide for the Toyota Highlander, covering common problems, features, maintenance costs and what to look out for before purchasing.