Premature downshift when making a turn

I've been having a sporadic problem that has me concerned. I have a 2003 Silverado with 195,000 miles on it and has been running flawlessly with no issues. However, if I am moving a cruising speeds and go to make a simple right or left hand turn without stopping (say at like speeds between 10-15 mph), the truck seems to downshift to 1st gear for a split second, then shifts hard into second. This doesn't happen all the time, and obviously I am not depressing the gas pedal too hard to make a turn. Any other time while driving, the transmission shifts very smoothly and is very responsive. I am just a bit concerned that this weird shift pattern may begin to cause damage since the truck is old and has high mileage.

I checked the fluid and it is full and clean, and does not smell burnt. The CEL is not on and no codes are stored in the computer.

Any thoughts?

I've been having a sporadic problem that has me concerned. I have a 2003 Silverado with 195,000 miles on it and has been running flawlessly with no issues. However, if I am moving a cruising speeds and go to make a simple right or left hand turn without stopping (say at like speeds between 10-15 mph), the truck seems to downshift to 1st gear for a split second, then shifts hard into second. This doesn't happen all the time, and obviously I am not depressing the gas pedal too hard to make a turn. Any other time while driving, the transmission shifts very smoothly and is very responsive. I am just a bit concerned that this weird shift pattern may begin to cause damage since the truck is old and has high mileage.

I checked the fluid and it is full and clean, and does not smell burnt. The CEL is not on and no codes are stored in the computer.

Any thoughts?

what is the idle RPM ? should be 650.

what is the idle RPM ? should be 650.

Yes it idles at 650 rpms.

Yes it idles at 650 rpms.

I would get some throttle body cleaner and clean up this and be sure that the throttle body does not stick when done .