Serpentine belt

[Edm]

Hi 

drive Toyota auris 1.2 T petrol 2015

my question serpentine belt seems to drive 5 pulleys or wheels 

one being engine pulley 

2 air con pulley

3 coolant pulley

4 alternator pulley

cant figure out what fifth pulley is for

also is there a separate pump for turbo unit coolant fluid

Have this car one year no problems just trying to learn how the new technology works

would be great to hear from somebody who has far more knollege than I 

Thanks to all

L

[Steve 10]

The tensioner pulley ?

I'm not familiar with the engine, so just a guess.

[eygo]

i'd go for the tensioner as well

 

[flash22]

Going clock wise.............................

A/C

Crank

Tensioner

Alternator

Idler

Water Pump

 

[Edm]

Thanks to Flash 22 , Eygo and Steve sounds like good info