Mercedes Benz ML320 2001

i have a SUV Mercedes Benz ML320 2001.
The car runs good as long as running at a regular speed, when i slow down or i stop at a traffic light.
the car turns on all the dashboard tlights and start beeping and the automatic shift box will only run like on 1st shift and will not shift.

but if i shot off the car immediatelly it will start running normally again.

Can any body help??? your help will be greatly appriciated. thank you.

If the check engine light is on get the codes and post them here.

Heck, even if the CEL isn’t on there’s still probably a code or two ready to be pulled

Sounds like a problem with system voltage.
Could be the charging system, weak battery or a slipping belt.
Get the battery voltage checked at idle; test the battery; inspect the serpentine belt.

If the charging system turns out to be the problem . . . the voltage regulator is quite often the problem. It can be replaced separately, and it’s not that difficult to do.

its a new battery,

auto zone put the comptuter on and no codes detected

the belt is fairly new