What to do if your 4×4 is not engaging?

1999 Super Duty trucks with electronic shift-on-the-fly 4WD have a problem with 4X4 not engaging properly or engaging when it shouldn’t. There are both temporary and permanent fixes for the problem. The temporary fix is to reset the computer by either disconnecting the batteries or by pulling fuse #15 from the fuse panel.

What to do if you have a 4WD problem?

You will hear it when you turn the truck to ON and engage 4wd, you disconnect a vacuum hose (pump senses drop in pressure and tries to re-pressurize), or if there is a vacuum leak the pump will just engage for a few minutes as soon as you turn truck to ON.

Why is my 1999 F350 4×4 not engaging?

What’s the system on a 2001 F350 4×4?

Here is some info on the system. The four-wheel drive, electronic shift-on-the-fly feature electrically shifts the vehicle transfer case between 2WD, 4X4, and 4X4 LOW. The system mode is selected by the operator through the mode select switch (MSS) on the instrument panel.

What to do if your 4WD engine is not working?

If the auto hubs don’t work then check all the vacuum lines and vacuum pump. There could be a blown fuse. most likely you have a 2 dollar seal thats broke causing enough air to leak to not engage the hubs… if you turn the knob to 4low, is the gearing like its in 4×4, just staying in 2wd?

What to do if your 4×4 is not engaging?