The 4WD Light Flashes, So What Does That Mean For You?

Four-wheel drive (4WD) is a driving system that is designed to provide improved traction and stability on slippery surfaces. This system allows the vehicle’s engine power to be distributed between all four wheels when needed, such as in low-traction conditions or when pulling heavy loads. The 4WD light flashing is a warning that your car’s 4-wheel drive system requires attention. If you’re not sure why it’s on, don’t worry. We’ll walk you through some possible causes and how to fix them.

The Reasons for the 4WD Light Flashing

When the 4WD light flashes on your dashboard, it means there is a problem with the 4WD system, and you should consult the owner’s manual for troubleshooting tips!

Here are 4 reasons why this light might flash:

The transfer case is overheated

If the transfer case is overheating, it can’t distribute the required power to the front and rear axles. So, the 4WD light starts flashing, indicating that there is something wrong with the transfer case. Sometimes, the flashing light means that the system has already been deactivated and needs some time for the overheated component to cool down.

4wd warning light
A 4wd warning light flashes. (Credit: Auto Expert)

You should check the owner’s manual to be sure what the flashing light refers to in this situation. If it’s indeed an overheated transfer case, pull over in a safe place and turn off your vehicle for an hour or so until the system cools down enough to function again.

The actuator does not work properly

The actuator helps engage and disengage the four-wheel drive system. With the help of a small electric motor, it makes switching between 2WD and 4WD as easy as just flicking a switch.

If the actuator isn’t working properly, it won’t be able to engage or disengage the gears when you switch into the 4WD or 2WD mode, respectively. So, this might cause a problem with the transfer case and the 4WD light might flash. You can check whether your actuator is working by using a multimeter to test the resistance of the actuator.

The rear diff locker does not engage properly

The rear diff locker makes it significantly easier to take sharp turns and cruise in challenging off-road conditions. It uses an electric actuator to engage inside the differential. If it fails to engage properly, the light will flash in red instead of orange.

To check whether the rear diff locker is working fine, drive at low speeds on a slippery surface (like sand). The vehicle’s front wheels should turn even if you turn the steering wheel at low speeds. If this doesn’t happen, it could be because the rear diff locker isn’t working right and your 4WD light is flashing.


Failure of sensors

There are multiple sensors located throughout the 4WD system. They transmit data about wheel speed, throttle position, and other important components to the 4WD system. If one or more of them malfunction, the light will flash, assuming that some components in the system are not working properly.

Check your owner’s manual to see which kind of sensors your car has for troubleshooting tips.


When the 4WD light flashes, it is best to consult your owner’s manual for troubleshooting steps. If you are not comfortable with auto mechanics or are in a hurry, have an automotive technician diagnose your 4WD system if you are willing to spend the extra cost.