my 2008( before face change model late 2008) superb had a new turbo fitted 6 months ago as it cut out when going up hills also sometimes when turning it on first time the turbo wouldn't come on, also eml light would come on. also when turning off engine a whining noise from the air reserve valve front bottom of engine.

all worked ok for a week then turbo would sometimes not come on and eml light would come on but no problems going up hills or under load.

re did the wiring from the ecu to turbo

replaced air mass meter

n75

map sensor

the air reserve sensor mentioned where the noise comes from.

g31

no more to change

has not cured the problems other than the eml light on permanently now

turbo doesn't come on when first turned on and whining noise FROM AIR RESERVE VALVE when turning off.

i think i have covered it all 

would any one have any suggestions please

many thanks graham

A proper diagnostic check using the dedicated VAG software or an accurate clone. Box swapping is futile and expensive.

 

rotodiesel.