Audi AMB Service Manual page 611

ENGINE 1.8 Liter 4-Cyl. 5V Turbo Engine Mechanical, Engine Code(s): AMB
Charge air pressure below specification
Charge air pressure above specification * See note
*If charge air pressure is too high, fuel supply will be interrupted in order to protect engine. This results in
2005 Audi A4 Quattro
2:37:37 AM
Wastegate bypass regulator valve N75 faulty -

-> Wastegate bypass regulator valve N75 ,
checking , checking
Hoses to Wastegate bypass regulator valve

N75 faulty, --> Boost pressure regulation
and vacuum control system, connection
diagram for vehicles up to 06.03 ,
connection diagram or --> Boost pressure
regulation and vacuum control system,
connection diagram for vehicles as of
07.03 , connection diagram
Charge pressure control valve in turbocharger

sticking in open position
Leak between turbocharger and intake

manifold --> Effects of leakage at intake
and exhaust end , effects
Mechanical air recirculation valve faulty -->

Mechanical air recirculation valve,
checking , checking
Recirculating valve for turbocharger N249

faulty --> Recirculating valve for
turbocharger N249 , checking , checking
Turbocharger faulty --> Turbocharger,

removing and installing , replacing
Vacuum unit for charge air pressure control

valve faulty --> Turbocharger, removing
and installing , replacing
Hoses to vacuum unit for charge air pressure

control (via N75 leaking --> Boost pressure
regulation and vacuum control system,
connection diagram for vehicles up to
06.03 , connection diagram or --> Boost
pressure regulation and vacuum control
system, connection diagram for vehicles as
of 07.03 , connection diagram
Charge air pressure control valve in

turbocharger sticking in closed position -->
Turbocharger, removing and installing ,
replacing
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