Hi folks, I have 2005 H2.
I recently noticed a click noise under the gear shifter when truck is in park only and at the same time I hit the brake. It only clicks once as in sync with the brake press.
Only thing I read that sounded close to my symptom was the "shift lock solenoid actuator".
I do pull some heavy loads on trailer and just yesterday I ran into my yards 6ft swinging gate with my trailer. Busting one light and for some reason, making other sides brake light go out too. I really didn't hit it hard enough to budge the Hummer, so I don't know if that's relevant to this issue. It was kinda odd how the problem was noticed at the same day.

Thanks for any advice and I'll check back very soon for any helpful guidance.

 

Normal for them to click