Checking coolant temperature sender G62 — VW

Checking
coolant temperature sender
G62
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 1551/1
or
V.A.G 1551/3
Test box
V.A.G 1598/31
Hand-held multimeter
V.A.G 1526C
Auxiliary measuring set
V.A.G 1594C
Current flow diagram
Test procedure
Connect
fault reader
V.A.G 1551
and select engine electronics control unit with
“address word 01”
. Engine must be idling.
Indicated on display:
Rapid data transfer HELP
Select function XX
Press keys
0
and
8
for function
“Read measured value block”
and confirm entry with
Q
key.
Indicated on display:
Read measured value block HELP
Input display group number XXX
Press keys
0
,
0
and
7
for
“Display group number 7”
and confirm entry with
Q
key.
Indicated on display:
Read measured value block 7 ->
15.4°C 15.9°C 16.7°C
Check coolant temperature value in display zone 4. The temperature value must Increase uniformly and without interruption.
In case of faults the fuel temperature or -5.4°C is displayed as a substitute.
If no realistic display appears in display zone 4, or either the fuel temperature or -5.4°C is displayed as a substitute, check
coolant temperature sender
G62
and line connections to
coolant temperature sender
G62
as follows:
Press
→
key.
Press keys
0
and
6
for function
“End data transfer”
and confirm entry with
Q
key.
Switch off ignition.
Vehicles with old connector type
Pull connector from
coolant temperature sender
G62
⇒ Fitting locations overview, Page
Chapter
Measure resistance between sender contacts 1+3.
Vehicles with new connector type
Pull connector from
coolant temperature sender
G62
⇒ Fitting locations overview, Page
Chapter
Measure resistance between contacts C + D on
coolant temperature sender
G62
.
Continuation for both connector types
Specification see diagram
Area A shows resistance values for temperature range 0...50°C and area 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 attained:
Renew
coolant temperature sender
G62
.
If specification is attained:
Connect
test box
V.A.G 1598/31
to control unit wiring harness.
Note
If necessary, left headlight may have to be released and placed to side to connect
test box
V.A.G 1598/31
Electrical system; Rep. Gr. 94; Lights, bulbs, switches - exterior
.
Vehicles with old connector type
Check lines between
test box
V.A.G 1598/31
and 4-pin connector for open circuit using current flow diagram. Contact 3+ socket 112, contact 1+ socket 104, 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
Vehicles with new connector type
Check lines between
test box
V.A.G 1598/31
and 4-pin connector for open circuit using current flow diagram. Contact 3+socket 112 Contact 4+socket 104 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
Continuation for both connector types
If no fault in lines is detected:
Renew
diesel direct injection system control unit
J248
Chapter
.