1995 AUDI A4 sensor

21-3


Connection diagram for charge air control
and vacuum pressure control

1 -
Activated charcoal filter (ACF)
2 -
EVAP Canister Purge Regulator valve -
N80-
3 -
Non return valve for ACF
Between ACF container and intake line in
front of exhaust turbocharger Note position (light side/ dark side) as
shown in Fig; arrow faces in direction of
flow
4 -
Air cleaner With Mass Air Flow (MAF) sensor -G70-
Pa
ge 3 of 17 Char
ge air s
ystem with turbochar
ger, checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.1

21-6


15 -
Non-return valve
Between ACF container and intake lineNote position (light side/ dark side) as
shown in Fig; arrow faces in direction of
flow
16 -
From Leak Detection Pump (LDP) -V144-
17 -
Charge air cooler With Charge Air Pressure sensor -G31-
18 -
Throttle Valve Control Module -J338-
19 -
Recirculating valve for turbocharger -
N249- Location: below intake line
20 -
Intake manifold With Intake Air Temperature (IAT) sensor -
G42-
Pa
ge 6 of 17 Char
ge air s
ystem with turbochar
ger, checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.1

21-14

Effects of leaks in intake or exhaust
system


Leak downstream of mass air flow sensor

Effect: Loss of power

Possible malfunction sources:

1 - Connection hoses between mass air flow
sensor and exhaust turbocharger

2 - Connection hose for crankcase vent

3 - Connection hose to mechanical air
recirculation valve
Pa
ge 15 of 17 Char
ge air s
ystem with turbochar
ger, checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.1

21-15

Leak downstream of exhaust turbocharger

Effect: Charge pressure too low

Possible malfunction sources:

1 - Connection hoses and line between exhaust
turbocharger and charge air cooler

2 - Hose between charge air cooler and intake
line

3 - Charge air cooler

4 - Seal of Charge Air Pressure sensor -G31- (in
charge air cooler)

5 - Sealing between throttle valve control
module and intake line

6 - Sealing between intake line and cylinder
head

Effects of leaks on exhaust side
Effect: Charge air pressure too low, possible
exhaust smell, soot traces in engine
compartment
Pa
ge 16 of 17 Char
ge air s
ystem with turbochar
ger, checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.1