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.

A: Hello and thanks for your question. When y...

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・Save up to 30%

Get a quote

What others are asking

Q: switching into 4hi from 2hi by itself

Your vehicle uses an electric transfer case motor to switch from 2WD to 4WD, and that motor or the associated wiring may be failing and switching itself over bumps. I would begin by checking the wiring and connectors to the...

Q: Traction Control System

The traction control system monitors the steering stability of the vehicle and engages when loss of traction has been detected. This is done by the use of electronic sensors that communicate with the Power Train Control Module (PCM) regarding steering...

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...

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...
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...