Checking charge pressure sender G31 — AUDI

Checking
charge pressure sender
G31
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526C
Auxiliary measuring set
V.A.G 1594C
Adapter cable, 121-pin
V.A.G 1598/31
(test box)
Vehicle diagnostic, testing and information system
VAS 5051B
with diagnosis lead
VAS 5051/1
Procedure
Note
The
charge pressure sender
G31
and the wiring connections are monitored by the engine control unit.
Connect up
vehicle diagnostic, testing and information system
VAS 5051B
with diagnosis lead
VAS 5051/1
, press
Vehicle self-diagnosis
key and select vehicle system
“01 - Engine electronics”
. When doing this, the engine must be running at idling speed.
Display on
VAS 5051
:
From list
1
, select diagnosis function
“02 - Interrogate fault memory”
.
If a fault relating to
charge pressure sender
G31
is displayed:
Terminate function
“02 - Interrogate fault memory”
by touching
←
key.
Press function
“06 - End output”
.
Switch off ignition and detach diagnostic connector.
Vehicles with halogen headlights:
Remove covers
1
and
2
at lock carrier (right-side) and above coolant expansion tank
arrows
.
Disconnect vacuum line
1
leading to activated charcoal filter from
throttle valve module
J338
.
Disconnect air intake hose
2
from
throttle valve module
J338
.
Rest-of-world vehicles with halogen headlights:
Remove nut
1
.
Lift off activated charcoal filter
2
and release hoses from retainers, etc.
Move activated charcoal filter aside.
USA models with halogen headlights:
Remove nut
1
.
Lift off vacuum reservoir
2
and release hoses from retainers, etc.
Move vacuum reservoir to side.
Vehicles with gas discharge headlights:
Remove right headlight
Rep. Gr.
94
.
All models:
Unplug electrical connector
arrow
at
charge air pressure sender
G31
.
Checking voltage supply
Connect
hand-held multimeter
V.A.G 1526C
to measure voltage between contacts
1
and
3
of connector for
charge pressure sender
G31
.
Switch on ignition.
Specification: approx. 5 V
If specification is not obtained:
Connect
adapter cable, 121-pin
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
108
3
98
Repair wiring connection if necessary.
If the specification is obtained:
Checking signal wire
Plug in connector at
charge pressure sender
G31
.
Connect
hand-held multimeter
V.A.G 1526C
(voltage measurement range) between sockets
“101”
and
“108”
on
V.A.G 1598/31
.
Start engine and run at idling speed.
Specification: approx. 1.90 V
Increase engine speed by depressing accelerator pedal briefly.
Specification: 2.00 ... 3.00 V
If the specifications are not obtained:
Check for open circuit and short to positive or earth in the following wiring:
Connector
Contact
V.A.G 1598/31
Socket
4
101
Repair wiring connection if necessary.
If wiring is OK:
Renew
charge pressure sender
G31
.