03 Ford expedition trac light

[Andre]

I have 03 expedition and my traction control/stability light is flashing and I believe my 4x4 isn't working due to that. Now when I change it to 4x4L I do feel the vehicle jerk as it should but still doesn't feel like 4x4 is working properly because I'm still fish tailing....what can I do or fix

[carriedi]

you should have your vehicle scanned to see if codes are stored that could be the cause of your problems. A wheel speed sensor may not be sending the correct signal. drive with the scanner monitoring the speed sensors and see it they all read the same speed with no signal drop outs.

you can scan the transfer case to check on the 4wd unit. Switches go bad, transfer case shift motors go bad could be vacuum line not passing vacuum or leaking vacuum.