Skip the auto shop - Our mechanics make house calls

Q: Why is my 4-wheel drive engaging while I'm driving?

asked by on

As I start to drive, not even reaching 10mph, I've gone about 4-6ft and my 4 wheel drive engages. I stop, put it in neutral, put it back to auto and after about 4-6ft more, it engages back into 4 wheel drive. What could be happening?

My car has 125000 miles.
My car has an automatic transmission.

A: Hey there. Driving with 4x4 on when it is n...

Hey there. Driving with 4x4 on when it is not needed can be rough on the axles, transmission, and hubs. The 4x4 engaging on its own can be the result of a mechanical error or an electrical error.

Mechanically if there is a vacuum leak in the system that engages the 4x4, the hubs can engage automatically if the wheels are rolling. There are other standards that need to be met for this to happen, which is why it is happening under certain conditions. There are a set of vacuum lines that run next to the battery that may need to be replaced.

There are several electrical components that have an effect on the system as well. Any issues like that would likely show on a diagnostic code scan.

If you would like to have this resolved, a certified technician from YourMechanic can come to your car’s location to inspect the transmission and advice you any corrections needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Will a drive shaft from a 93 chevrolet 1500 4×4 fit in a 05 chevrolet avalanche 2wd

The two driveshafts are most likely different lengths due to one being a 4wd and the other 2wd. You could lay them side by side and compare them to see if they are the same, but I doubt that this...

Q: Turn signals not working

Hello, there are several steps you can take to see what solution can be found. The multifunction switch are not to fail with age and use. Turn on your hazard light switch. If the light start flashing like they should,...

Q: Truck dying and oil pressure dropping to 0

Your vehicle has a fair amount of miles on it, but the pressure reading should still come up when you are driving. With a new pressure sending unit and a new oil pump, there must be a blockage inside the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...