4x4 Issue

[scubanero]

I have been through some very long 4x4 control threads, but have not seen symptoms exactly like mine: 4x4 Auto seems to work normally. 4x4 Low seems to work normally. Pushing the 4x4 High button lights up the indicator for a few seconds, but then it goes out. I haven't pulled anything apart yet and I haven't jacked it up to see whether the front wheels are being driven or not. No grinding noises nor any indication that 4x4 is engaged when it shouldn't be.
Does anyone know whether these symptoms point to the control module, or the shift motor?

Thanks.

 

[stahrman]

When you said the 4x4 high button lights up the indicator, do you mean the little light on the dash or the 4x4 high that lights up on the speedometer gage?

 

[scubanero]

When you said the 4x4 high button lights up the indicator, do you mean the little light on the dash or the 4x4 high that lights up on the speedometer gage?

On the instrument panel, but then it goes out 2 seconds later.

 

[stahrman]

Can't help you there....still learning....bought my x 5 days ago...lol. At first I thought my 4x4 low didn't work because the light on dash would just keep blinking then turn off??? I didn't realize truck had to be completely stopped in neutral and brake pedal has to be pressed before 4x4 low shows up on instrument panel..

 

[Exproblems]

I have been through some very long 4x4 control threads, but have not seen symptoms exactly like mine: 4x4 Auto seems to work normally. 4x4 Low seems to work normally. Pushing the 4x4 High button lights up the indicator for a few seconds, but then it goes out. I haven't pulled anything apart yet and I haven't jacked it up to see whether the front wheels are being driven or not. No grinding noises nor any indication that 4x4 is engaged when it shouldn't be.
Does anyone know whether these symptoms point to the control module, or the shift motor?

Thanks.

From what I've read in here over the last few years, the 4x4 control module seems to be the culprit on 4x4 issues. The "4x4 High" dash light should stay lit up when 4x4 high is engaged.

 

[scubanero]

Just to close this off: The module was indeed the culprit. It only failed to engage the front shaft clutch. The shift motor always worked and the control module shifted it, but it was only 2L not 4L. New TM-153 and all is well.