Skip the auto shop - Our mechanics make house calls

Q: 4x4 issues

asked by on

When I shift from 2wd to 4wd the screen says 4x4 shift in progress then 3 seconds later a wrench appears and says check 4x4 and it doesn't engage. The vacuum solenoid keeps constant vacuum and when shifted into 4x4 there should be no vacuum. I replaced the solenoid and it's still doing it.

My car has 88000 miles.
My car has an automatic transmission.

Hello and thanks for your question. When you shift from 2WD to 4WD the vacuum solenoid is to help switch the transfer case from 2WD to 4WD a slow to no speed. If you changed the vacuum solenoid and nothing changed, try checking the vacuum hose from the engine to the solenoid to see if there are any leaks.

If there is solid vacuum on the hose to the solenoid, then the switch motor on the outside of the transfer case could be failing. Try tapping on the switch motor and then retest. If the transfer case kicks into 4WD, then the switch motor needs to be replaced. If the transfer case still does not go into 4WD, then check the harness to the motor and make sure that the harness is not burnt or corroded.

Check the fuse box for the fuse that controls the motor and see if the fuse is burned. If you checked all everything on your 4WD, you could have a motor that is stuck, a chain could be broken inside the transfer case, or the clutch slider could be damaged inside the transfer case. I recommend checking the switch motor and if it doesn’t work then replace it. If you need help troubleshooting your transfer case, have a certified mechanic, like one from YourMechanic, inspect the shifting problem and advise you on a repair.

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

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: Need to know the backlash specifications for a 2006 Denali transfer case.

Hi there. On most applications that deal with gear lash or known as backlash there is very low amounts of lash to prevent damage to the gears but also allowing the metal to expand. For your transfer case, set the...

Q: Front end vibration and loss of wheel weight on a '96 Ford Explorer

It would if it happens at higher speeds. It wouldn't affect it if you are going 10, 20, 30 mph, but if you are going 50-60 mph and it begins to happen, then yes. Go get it balanced and have...

Q: car is vibrating when stopped

Hi Kionna. Thanks for contacting us today. In most cases, a vibration as you are describing is caused by loose vacuum line, which was likely removed during their service. However, it could also be an indication of low transmission fluid...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
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...