Checking exhaust gas temperature sender 1 G235: Audi 1.8 (AMK, AMU, APX, APY, …)

Checking
exhaust gas temperature sender 1
G235
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526 C
or
V.A.G 1526 A
Voltage tester
V.A.G 1527 B
Auxiliary measuring set
V.A.G 1594 C
or
V.A.G 1594 A
Adapter cable
V.A.G 1598/31
(test box)
Vehicle diagnostic, testing and information system
VAS 5051
Procedure
Note
The
exhaust gas temperature sender 1
G235
and the wiring connections are monitored by the engine control unit.
Connect up
vehicle diagnostic, testing and information system
VAS 5051
with
diagnosis lead
VAS 5051/1
, press
vehicle self-diagnosis
button and select vehicle system
“01 - Engine electronics”
. Engine must be idling.
Display on
VAS 5051
:
From the list
1
select diagnostic function
“08 - Read measured value block”
.
Display on
VAS 5051
:
Press keys
1
1
2
on keypad
2
to select
“Display group 112”
and confirm entry by pressing key
Q
.
1
Enter display group
Display on
VAS 5051
:
Check display in zone
1
.
Increase engine speed.
The exhaust gas temperature should rise.
Press the
←
button to exit from the function
“08 - Read measured value block”
.
Press function
“06 - End output”
.
Switch off ignition and detach diagnostic connector.
If the exhaust gas temperature remains constant or if an implausible value is displayed:
Checking voltage supply
Fuse for
exhaust gas temperature sender 1
G235
OK
Current flow diagrams, Electrical fault finding and Fitting locations
.
Fuel pump relay
J17
OK
Current flow diagrams, Electrical fault finding and Fitting locations
.
Note
The voltage supply for the
exhaust gas temperature sender 1
G235
is taken from
fuel pump relay
J17
.
Remove cover in front of intake manifold.
Unplug electrical connector
arrow
at
exhaust gas temperature sender 1
G235
.
Connect
voltage tester
V.A.G 1527 B
between contact
3
of connector for
exhaust gas temperature sender 1
G235
and earth
“–”
.
Operate the starter briefly.
The LED should light up.
If LED does not light up:
Check for open circuit in wiring from contact
3
of connector for
exhaust gas temperature sender 1
G235
via fuse to
fuel pump relay
J17
Current flow diagrams, Electrical fault finding and Fitting locations
.
Repair wiring connection if necessary.
If the LED lights up:
Checking wiring
Connect
adapter cable
V.A.G 1598/31
(test box) to connectors of wiring harness; do not connect engine control unit. Connect earth clip of test box to earth
arrow
Rep. Gr.
24
.
Caution
To prevent damage to electronic components, select appropriate measuring range before connecting measuring leads and observe test requirements.
Check for open circuit and short to positive or earth in the following wiring:
Connector
Contact
V.A.G 1598/31
Socket
1
(signal)
61
2
(earth)
50
Repair wiring connection if necessary.
If no fault is found:
Renew
exhaust gas temperature sender 1
G235
.