Connect vehicle system tester -V.A.G 1552-. Start engine and select address word 01 “Engine electronics” → Chapter.
–
Select function 08 “read measured value block” and display group number 001.
–
Observe the coolant temperature in display field 4.
Specified value: the temperature reading must rise evenly
In the event of a fault the fuel temperature or value -5.4 °C is displayed instead.
If an implausible value is displayed in display field 4 or if the fuel temperature is displayed instead:
–
Select function 06 “End output” and confirm entry with Q.
–
Switch off ignition.
–
Remove engine cover.
Reading measured value block 1 ->
900 rpm 5.2 mg/stroke 5.1°CA 20.6°C
–
Disconnect plug -1- from Coolant temperature sender (-G62-) -2-.
–
Connect handheld multimeter to measure the resistance onto both contacts of the coolant temperature sender (-G62-) -2-.
Specified value:
The specification in field -A- applies to the temperature range 0 to 50 °C, the specification in field -B- applies to the temperature range 50 to 100°C.
Read out examples:
t
The specification for a temperature of 30 °C is 1500 to 2000 Ω
t
The specification for a temperature of 80°C is 275 to 375 Ω
If the specified value is not reached:
–
Replace the coolant temperature sender -G62-.
If the specified value is reached:
–
Connect test box -V.A.G 1598/31 - to the wiring loom on the engine control unit → Chapter.
–
Check the following wire for interruption or short-circuit to earth or positive:
Connector -1-, contact
Test box -V.A.G 1598/31-, bush
1
112
2
104
–
Also check the wires for short-circuits.
–
If necessary eliminate wire interruption or short-circuit.