1999 AUDI A4 wiring

21-40

Test requirements:

Vehicle diagnostic, testing and information
system VAS 5051 or VAG 1551Scan Tool
connected.

Test sequence

Note:
The Charge Air Pressure sensor -G31- and the
wiring connections are monitored by the engine
control module.

- Read Diagnostic Trouble Code (DTC) memory
of engine control module.
If a DTC relating to the Charge Air Pressure
sensor -G31- is displayed:

Checking power supply

- Disconnect connector -arrow- on charge pressure sender.
Pa
ge 31 of 34 Char
ge pressure leak test with VAG 1687
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.2

21-41


If specified value is not attained: - Connect multimeter between contacts 1 and 3 of connector to measure
voltage.
- Switch ignition on.
Specified value: approx. 5 V

Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Fuel Injection & Ignition,
Engine Code(s): AWM, Repair Group 24
- Connect VAG 1598/31 test box to wiring harness leading to engine
control module; engine control module must also be connected.
Pa
ge 32 of 34 Char
ge pressure leak test with VAG 1687
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.2

21-42


If specified value is attained:
Checking signal wire - Check for open circuit and short to positive or Ground in following
wiring connections: Connector
contact
Test box VAG 1598/31
1 108
3 98
- Repair any open/short circuit as necessary.
- Attach connector from charge air pressure sensor.
- Attach multimeter for voltage test to socket 101 and socket 108 of test
box.
- Start engine and run at idling speed.
Specified value: approx. 1.90 V
- Bring engine to speed by spontaneous acceleration.Specified value: 2.00...3.00 V
Pa
ge 33 of 34 Char
ge pressure leak test with VAG 1687
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.2

21-43
If specified values are not attained:

If the wiring is OK: - Check for open circuit and short to positive or Ground in following
wiring connection: Connector
contact
Test box VAG 1598/31
4 101
- Repair any open/short circuit as necessary.
- Replace Charge Air Pressure sensor -G31-.
Pa
ge 34 of 34 Char
ge pressure leak test with VAG 1687
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE06.21.2