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.

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 1,000 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
  1. Home
  2. Questions
  3. Why is my 4-wheel drive engaging while I'm driving?

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: How do you use the four-wheel drive system?

If your car is so equipped (optional), the four-wheel drive system offers intelligent operation and limits the input you need to provide to activate and operate it. If you’ve never driven a vehicle with an intelligent four-wheel drive system, here’s...

Q: Car won't reverse but drives fine. Will pop in reverse around 3000 rpms.

Your problem is probably due to wear in the transmission. The mileage is about right. The transmission operates using hydraulic pressure generated by an internal pump. As the fluid pump and other components wear, the clearances inside them increase and...

Q: Smart Entrance Control Module needs replacing

The SECM may be ok. It may have a power issue due to a blown fuse or relay. The SECM is an expensive part and may require factory level programming. I suggest having a qualified technician fully inspect your vehicle's...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...