1995 AUDI TT catalytic converter

24-100

Test requirements:

Coolant Temperature at least 80 C.

Fuse for oxygen sensor heating OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations

Test sequence

or
Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 4-pin harness connector -2- (black) to Heated Oxygen
Sensor (HO2S) -G39- before catalytic converter.
- Disconnect 4-pin harness connector -1- (brown) to Oxygen Sensor
(O2S) behind Three Way Catalytic Converter (TWC) -G130-.
Pa
ge 30 of 37 Ox
yg
en sensor control, 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.FU06.24.2

24-104


Oxygen Sensor (O2S) heater -Z19- for oxygen sensor before catalytic
converter:
Oxygen sensor heater 1 -Z29- for oxygen sensor behind catalytic
converter:
If wire connection is OK, but there is no Ground (GND) supply for oxygen
sensor heating: - Check following wire connection for open circuit:Harness connector
Terminal
VAG1598/31 test box
Socket
2 5
Harness connector
Terminal
VAG1598/31 test box
Socket
2 63
- Repair open circuit if necessary.
- Replace Engine Control Module (ECM) Page 24
-23
Pa
ge 35 of 37 Ox
yg
en sensor control, 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.FU06.24.2

24-105

Oxygen sensor, removing and installing


Special tools and equipment

3337 wrench, 7-piece set
Locking compound G 052 112 A3

Procedure

Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access harness connectors. The coolant hoses
can remain connected. - Disconnect 4-pin harness connector of oxygen sensor and lay it to
side.
1 - (brown) for Oxygen Sensor (O2S) behind Three Way Catalytic
Converter (TWC) -G130-
2 - (black) for Heated Oxygen Sensor (HO2S) -G39- before catalytic
converter
- Unscrew oxygen sensor using special tool 3337.
Pa
ge 36 of 37 Ox
yg
en sensor control, 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.FU06.24.2