4x4 will only engage with fuse pull reset

[Dr Klaun]

Hi! A new member here!

I've got an 02 Ranger 4x4 "off road" (not FX4, Level II), ex. cab / styleside with the 4.0 and 5 spd AT.

On a wintery day this past spring I found out that the switch for the 4x4 no longer worked.... After searching the web and reviewing the symptoms I'm kind of stumped on the issue. Currently it will only shift into 4x4 if I pull the fuse for the selector switch (in the fuse box on the drivers end of the dash, not under the hood) and put it back in. The dash switch then makes the audable "click" and will shift. Then after sitting overnight it will no longer shift. I hear no audible "click" from the switch / electronic brain at the right footwell unless I do the fuse trick again.

Any thoughts on whether it's the switch or the "elec brain" in the passanger footwell? Or some other gremlin? I'd like to get this fixed sometime this fall while I have the time.

 

[feellnfroggy]

Welcome to TRS, theres a a sunny side to seattle? j/k I have never heard of your problem with any fused item, however while your waiting on other responses, check the tech library for some of the common fixes and maintenance issues. Theres some good writeups. Its possible that the 4x4 module behind your seat is going bad. Theres also a writeup on how to test it.

It won't be the ECU (electric brain)

 

[Dr Klaun]

Theres some good writeups. Its possible that the 4x4 module behind your seat is going bad. Theres also a writeup on how to test it.

It won't be the ECU (electric brain)

Thanks for the response! I think I posted a bit of a mix-up on words - I meant the elec. 4x4 module when I was talking about elec. "brain". Mine is in the passanger footwell. I'll try and find the tech article for testing.

 

[Dr Klaun]

OK, a bit more information!

After reviewing some past threads I found on this, it seems some others have had this same issue but I found no solutions posted

The 4x4 control module for my 02MY is behind the passager footwell kick panel in front of the door. It's held on with 2 screws. There is no switch / LED test light, like what is described in the tech section (for 1990's era Rangers).

I unscrewed the CM and opened it up to expose the circuit board. It looked fine with some minor residue on one of the connectors:

I cleaned these up and plugged the unit back in and voila! The 4x4 worked!

But..... after about 30 minutes it would no longer work again. This is the same problem as when I would pull the fuse or remove the battery cable. It works directly after that, then stops working after a short duration. Anyone have thoughts on this?

Here's the sticker on the CM:

 

[Jon4x4]

Sounds like it could be losing connection while sitting around. Try some duck tape

 

[feellnfroggy]

Hmmm.....found it.

MOTOROLA

 

[Whisky]

I see this post is kinda old but I have the exact same problem. Any solutions?

 

[vitalka89]

Bump..
Does anyone know the solution to this? Im having the same problem.