sensor AUDI A4 1997 B5 / 1.G AEB ATW Engines Charge Air System With Turbocharger Workshop Manual

21-66


Charge air pressure sensor -G31-,
checking

Special tools and equipment

VAG1526A
VAG1594A
VAG1598/31
VAS5051 with VAG5051/1
- or
VAG1551 with VAG1551/3A
Pa
ge 25 of 42 Char
ge air s
ystem with turbochar
ger
(en
gine code ATW
)
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21-67

Note:
The charge air pressure sensor -G31- and wire
connections are monitored by the Engine Control
Module (ECM).

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word 01". Engine must run at idle
for this:

Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel
Injection & Ignition, Repair Group 01
- Check DTC memory of Engine Control Module
(ECM):

Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel
Injection & Ignition, Repair Group 01 If a malfunction relating to the charge air
pressure sensor -G31- is indicated:

Checking voltage supply

- Disconnect harness connector at charge air
pressure sensor.
Pa
ge 26 of 42 Char
ge air s
ystem with turbochar
ger
(en
gine code ATW
)
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21-69

Checking signal wire

- Connect harness connector at charge air
pressure sensor.

- Connect multimeter to socket 101 and socket
108 of test box for voltage measurement.

- Start engine and run at idle.


Specified value: approx. 1.90 V

- Bring up engine RPM by suddenly depressing
pedal.

Specified value: 2.00-3.00 V
If specified values are not obtained:

- Check the following wire connection for open circuit and short circuit to
Ground (GND) and B+: Harness connector
terminal
VAG1598/31 test box
socket
4 101
- Repair open circuit or short circuit if necessary.
Pa
ge 29 of 42 Char
ge air s
ystem with turbochar
ger
(en
gine code ATW
)
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If wire connection is OK:
- Replace charge air pressure sensor -G31-.
Pa
ge 30 of 42 Char
ge air s
ystem with turbochar
ger
(en
gine code ATW
)
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p://127.0.0.1:8080/audi/servlet/Dis
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yp
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pair&id=AUDI.B5.GE02.21.3

21-71

WARNING!

Use only approved air fittings to adapt shop
air supply line to VAG 1687 tester.

Special tool VAG 1687/1 pressure adapter,
installing (1.8L Turbo)

- Separate intake hose from Mass Air Flow (MAF)
sensor assembly.

Special tool VAG 1687/1 pressure adapter, installing (2.7L BiTurbo)
Repair Manual, Maintenance; Air cleaner housing, cleaning; Air cleaner element, replacing
- Insert VAG 1687/1 pressure adapter in intake hose -black arrow- using
existing clamp (as shown).
- Remove crankcase ventilation tube from intake hose at -white arrow-.
- Remove upper air cleaner housing and hoses to intake manifold as
necessary

- Insert VAG 1687/1 pressure adapter in intake hose -white arrow- using
existing clamp (as shown).
- Disconnect engine crankcase ventilation hose from intake manifold -
black arrow-.
-
Plug intake manifold fitting (for crankcase ventilation hose) with
appropriate hose and metal plug using clamps supplied with VAG
Pa
ge 33 of 42 Char
ge air s
ystem with turbochar
ger
(en
gine code ATW
)
11/18/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE02.21.3