Will not go into 4X4 mode

[tpeek]

I have a 2002 XLT with the push button controls on the dash. I have tried several times to engage 4 wheel drive high and low. I have followed the owners manual exactly. Nothing happens when I press the buttons. I have checked all the fuses and all are good. Can anyone help? Thanks

 

[Ray Lobato]

How do you know that it is not going into 4wd, by the lights?
Please give us as much information as you can. Any sounds ,lights going on, or not going on. I could be a number of things, depending on what information you can furnish.

 

[gijoecam]

Check Fuse #12 in the central junction box (5A).

There are a ton of inputs into the 4wd control module.... that's the obvious one that feeds the switch. If that doesn't fix it, it'd be easiest to pop in at the dealership and have them connect it to the diagnostic scanner. They'll be able to tell you what's not getting or sending a signal in a matter of minutes.

-Joe

 

[tpeek]

No 4X4

To answer your questions there are not lights on the dash that indicates the transfer case is being activated, no sounds at all. Even when he rear wheels slip the front does not engage as it did a few months ago. The deal did replace the switch that allows the driver to place the gear shift into park. Could the repair person possibly disconnected the dash buttons and did not replace them? Thanks for your help.

 

[Wash X]

I have the same problem. i ordered a 4x4 control module for it. I asked the parts guy and he told he sells a few of these and he nicely went to the back and asked a tech. He told him they had a problem with the 02 modules and they have been superceded 3 times. I hope it fixes it. It should be here at the end of the week.

 

[Ray Lobato]

If you aren't getting the light in 4Hi, then the solenoid in the front part of the transfercase is not engaging. This is not the transfercase motor, as it only moves when you go into 4LO. Sometimes the solenoid will get stuck. If you take a rubber head mallet and bang on the front of the transfercase while the switch is in 4HI, it may engage. I have done this on my Explorer, when I still had the stock transfercase in it. If that doesn't do it, then you will need to have the codes read. If you have an OBDII, then you can read these yourself, or go to the dealer and have them read it.
There are 2 electrical connectors going to the transfercase. One goes to the transfercase shift motor. Its a pretty big connector, towards to back of the transfercase. The other one goes to the transfercase solenoid, which is towards the front of the transfercase. It has only 2 or 3 wires IFRC ans is sitting on top. Check to see if those 2 connectors are infact connected. Usually if the shift motor connector is not connected, it will make your 4wd lights blink, so if might be connected but not properly or enough to make a good contact. Hope this helps. Please keep us informed

 

[Wash X]

I checked for codes and there were none. I have no lights on the switches. pressing them does nothing. I'll know in a few days if the module is the problem.

 

[gijoecam]

If you aren't getting the light in 4Hi, then the solenoid in the front part of the transfercase is not engaging. This is not the transfercase motor, as it only moves when you go into 4LO. Sometimes the solenoid will get stuck. If you take a rubber head mallet and bang on the front of the transfercase while the switch is in 4HI, it may engage. I have done this on my Explorer, when I still had the stock transfercase in it. If that doesn't do it, then you will need to have the codes read. If you have an OBDII, then you can read these yourself, or go to the dealer and have them read it.
There are 2 electrical connectors going to the transfercase. One goes to the transfercase shift motor. Its a pretty big connector, towards to back of the transfercase. The other one goes to the transfercase solenoid, which is towards the front of the transfercase. It has only 2 or 3 wires IFRC ans is sitting on top. Check to see if those 2 connectors are infact connected. Usually if the shift motor connector is not connected, it will make your 4wd lights blink, so if might be connected but not properly or enough to make a good contact. Hope this helps. Please keep us informed

It's actually not a solenoid, but an electromechanical clutch. Banging on it should not have made any difference.... If the light's not coming on in a second gen, there's no power getting to it. Bypassing it with a jumper wire can force it to engage 100% in a bind.

In a 3rd gen, however, the signal goes from the 4wd module, through the clutch coil, and back through the module. That's how it knows whether or not it's engaged (instead of just sending the signal and relying on blind faith). If it fails to engage, it'll know.

If it's trying, the button should still light up. For whatever reason, it's not. Without hooking it up to a WDS monitor to see what inputs/outputs are/aren't being made, you're just shootin' crapps. In this case, it may be worth it to pay the hour's fee for the diagnostic to pin-point the problem.

-Joe