I just bought a 06 Sierra and compared to other Chevy trucks I have owned with tow/haul option it seems odd the way it works. I thought at first it did not work at all, I would push it and indicator light would come on but nothing would happen ! Then I discovered it would only lock up at speeds of 50 mph or below and would automatically shift out at 58-59 mph on it own !
I had it in the Chevy dealer for a follow up on another subject and described it to the service writer, they drove it and said it worked correctly and they could not find a service adviser on tow/haul problems. And here I have read several different problems on them!
Can anyone tell me if the way mine works is correct or not !? I have had vehicles with tow/haul and they all pretty much engaged and stayed engaged until you would turn it off.