4wd on it's own

[Inspector4]

Our new to us 2007 TrailBlazer shifts it's self into 4 Hi and the 4Lo light blinks. Had it to the dealer said no codes were showing, and they could not duplicate the problem.
They put 1 mile on the TB road testing, said that they checked the selector switch and it is fine. Anyone else with a newer TB having this problem?
All the threads about this problem seem to be older TB's.
It locked into A4wd today on a dry Interstate @ 70+ MPH. Turned selector switch to A4wd and back to 2hi and it went back to 2hi while in A4wd the 2hi light was blinking.
From what I have read in the other threads it is either the switch or the TC Controller, any other thoughts?Are either of these parts covered under the warranty
The dealer gets it back Wed AM.
We got such a screaming deal on it I will put up with a little BS from the Chevy dealer,(they did not sell it to us).
Mike

[RayVoy]

From what I have read in the other threads it is either the switch or the TC Controller, any other thoughts?Are either of these parts covered under the warranty
MikeMike, welcome to the site.
The problem is the switch or the TCCM, I don't know which. Both should be covered by the warranty.

[WOOLUF1952]

:iagree: If you bought it new it should be under warranty. But, if you didn't buy it from that dealer, they may balk at doing warranty work. Also, :tiphat Welcome :tiphat

[TheWETZ]

My 2002 TB LTZ started shifting to 4wd on it's own (it has 63,000 on the clock). This would only happen when driving or at least when it was rolling. When it would shift over the LED on the selector switch would show it was still in 2HI when in fact it was in 4wd.
It didn't throw any codes so I disconnected the battery for a few minutes. So far the TB has not shifted on it own, and I hope that fixed the problem.
So theres some food for thought, good luck.

[Inspector4]

Sent it back to the dealer with pictures of the lights in 4hi and of auto 4 with the switch clearly in 2hi. They replaced the switch it hasn't happened since. The last time it engaged on it's own I was on the Interstate going 72MPH, I knew when it engaged.
I don't know if it's related to the repair but now the curb view does not return to the correct spot. Any thoughts?
Mike