I have an '04 H2 and I am having issues with the system dropping into 4 Hi LOCK intermittently. The Dealer says no problem (after they experienced the problem and tore the transfer case apart for an exploratory $$) Their professional opinion was a tire problem. Can unequal tire circumference cause the drive train to drop into 4 Hi LOCK? I know the AWD would get a workout transferring torque. But can this affect 4W LOCK?
Since this has been happening (just over the last 3 or 4 weeks) it's wearing my tires by crow hopping and scrubbing the rubber off when turning. I'm apprehensive to put new tires on until I'm sure of the root cause. Seeing that I have not had this problem until a few weeks ago, I'm wondering if the sudden tire wear is a symptom rather than the disease...

Any thoughts? BTW- No error codes found

 

are there different size tires on your rig? or did you incorporate a newer tire to the older ones?

 

My tires are factory original (only 45k on an '04). They are beginning to wear improperly because of this recent problem with intermittently dropping into 4WD LOCK and scrubbing the tires. I'm digging for the root cause. I'm no expert but I can't see how tire circumference issues can make force AWD to drop into 4WD LOCK. Are the systems related? I experimented by letting some air out of one of the front tires to see if I could force this issue to manifest. No luck. It's totally intermittent. I'm stumped and so is the dealer.

 

I agree, not with four OEM tires. I would have asked the dealer if there is a GM service bulletin regarding the issue. My gut would be to suspect a faulty switch or other electrical problem. But then, I'm no expert either.