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Q: 4x4 issues

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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.

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