2007 GMC Sierra Denali Questions

Get answers to questions about your 2007 GMC Sierra Denali at RepairPal. Find solutions, diagnose problems and get back on the road.

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Not sure which Denali I have Just says Denali on door. But I bought it used a month ago love it so far, But experienced a problem just before Christmas with auto lights, put vehicle in drive and head lights did not come on after messing with switch for few minutes then started working. Now if you go to bright and back sometimes the lights go out. But if you place back in bright come back on. What can I do to repair this I really like my Denali.

it is real loud, dealer can not seem to repair

So I have had this truck 1 yr now and recently the tranny feels like it is staring to hit gears harder. Especially when slowing to a red light but then accelerating as it turns green, it down shifts then feels like it gets confused and finally hits up a gear. I have 69K miles and figure the tranny fluid and filter needs changing. Any thoughts?