service 4wd light on

[yukonrob]

4wd has been working fine...today the service 4wd light came on and wouldn't go into 4wd. I unhooked the neg batt terminal thinking it would reset something and it worked. probably temp fix. anyone give me some advice...thanks

 

[BRUTUS_T_HOG]

Clean up the grounds under the drivers door hinge on the body mount bracket and disconnect battery again. There is a TSB for cleaning the ground and the encoder motor position switch also sometimes needs to be replaced.

My Yukon does this from time to time I usually just shift through all the transfer case positions and it goes away for a while. Cleaning the ground significantly helped

 

[SunlitComet]

Your Autotrac 4wd system is storing a trouble code that will explain why there is a problem but you will need to get your hands on the right scanner to interface with the TCCM. Find a shop equipped with a high end Snap-on or OTC scanner. You can not access it any other way.

 

[yukonrob]

thanks a lot guys...I will try this and see what happens.