Checking intake manifold temperature sender G72 — VW

Checking
intake manifold temperature sender
G72
Special tools and workshop equipment required
Fault reader
V.A.G 1551
or
vehicle system tester
V.A.G 1552
with
diagnosis cable
V.A.G 1551/3
Adapter cable, 121-pin
V.A.G 1598/31
Hand multimeter
V.A.G 1526C
or
multimeter
V.A.G 1715
Auxiliary measuring set
V.A.G 1594C
Current flow diagram
Test procedure
Connect
fault reader
V.A.G 1551
or
vehicle system tester
V.A.G 1552
and select engine electronics control unit with
“address word 01”
. Engine must be idling. (Connecting fault reader and selecting engine electronics control unit
Chapter
.)
Indicated on display:
Rapid data transfer HELP
Select function XX
Press buttons
0
and
8
for function
“Read measured value block”
and confirm entry with
Q
button.
Indicated on display:
Read measured value block HELP
Input display group number XXX
Press buttons
0
,
0
and
7
for
“Display group number 7”
and confirm entry with
Q
button.
Indicated on display:
Read measured value block 7 ->
15.4°C 15.9°C 16.7°C
If no realistic display appears in display zone 3 or a substitute temperature of 136.8°C is displayed, check
intake manifold temperature sender
G72
and line connections to sender as follows:
Press
→
button.
Press buttons
0
and
6
for function
“End data transfer”
and confirm entry with
Q
button.
Switch off ignition.
Engine codes AGR, AHF, ALH, ASV
Remove right headlight
Electrical system
Rep. Gr.
94
Removing and installing headlight
Remove connector from
intake manifold pressure sender
G72
Chapter
.
Measure resistance between sender contacts 1+2.
Specification see diagram.
Scale A shows resistance values for temperature range 0..50°C and scale B the values for temperature range 50..100°C.
Examples:
30 °C corresponds to a resistance of 1500..2000 Ω
80 °C corresponds to a resistance of 275..375 Ω
If the specification is not achieved:
Renew
intake manifold temperature sender
G72
.
If the specification is attained:
Connect
adapter cable, 121-pin
V.A.G 1598/31
to control unit wiring harness.
Check wiring between
adapter cable, 121-pin
V.A.G 1598/31
and connector for open circuit referring to current flow diagram.
Contact 1+socket 52 Contact 2+socket 73 Line resistance: Max. 1.5 Ω
Also check wiring for short to one another, short to vehicle earth and short to battery positive.
Specification: ∞ Ω.
If no fault in lines is detected:
Renew
diesel direct injection system control unit
J248
Chapter
.
Engine codes AGP, AQM
Pull connector
1
off
intake manifold temperature sender
G72
2
.
Measure resistance between sender contacts.
Specification see diagram.
Scale A shows resistance values for temperature range 0..50°C and scale B the values for temperature range 50..100°C.
Examples:
30 °C corresponds to a resistance of 1500..2000 Ω
80 °C corresponds to a resistance of 275..375 Ω
If the specification is not achieved:
Renew
intake manifold temperature sender
G72
.
If the specification is attained:
Connect
adapter cable, 121-pin
V.A.G 1598/31
to control unit wiring harness.
Check wiring between
adapter cable, 121-pin
V.A.G 1598/31
and connector for open circuit referring to current flow diagram.
Contact 1+socket 73 Contact 2+socket 54 Line resistance: Max. 1.5 Ω
Also check wiring for short to one another, short to vehicle earth and short to battery positive.
Specification: ∞ Ω.
If no fault in lines is detected:
Renew
diesel direct injection system control unit
J248
Chapter
.