Spheros Thermo S 160, Workshop Manual

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Thermo S 160/230/300/350/400 5 Troubleshooting and error correction
517
5.5.12 Solenoid valve inspection
CAUTION
The coil of the solenoid valve can heat up in switched-on
condition.
The solenoid valve must only be completely replaced.
In case of replacement or assembly a new gasket ring
must be used.
NOTE
Due to system characteristic s draining the space between
solenoid valve and nozzle bore may cause fuel dripping
from the atomizer nozzle for a short period of time.
A leaking valve seat of the so lenoid valve can be indicated
by smoke development in th e heater during the run-down.
Fuel drips from the atomizer nozzle.
A not closing solenoid valve may cause heater deactivation
during run-down with heater interlock activation.
It is possible to manually test the electrical functionality of
the solenoid valve, and using the Component Test menu
of SST diagnosis.
Inspection using SST diagnosis
t Remove burner (see 8.2).
t
Connect the test plug to the adapter wiring harness.
t
Connect the heater to the vehicle electrical system.
t
Connect the SST diagnosis adapter to the heater and
a PC via the interface in the heater wiring harness.
Start SST diagnosis, establish connection to the
heater and open the Component Test menu.
t Select and start the solenoid valve in the Component
Test menu.
t The solenoid valve must audibly open.
t
After the test is completed, exit SST diagnosis as needed.
t
Disconnect the heater from the vehicle electrical system.
t
Disconnect the test plug.
t
Install burner (see 8.2).
Manual inspection:
t Remove burner (see 8.2).
t Disconnect the solenoid valve plug from the control unit.
t Check the electrical functionality by applying direct
voltage:
– Opening voltage: starting at 17.0 Volt
– Power consumption at
24V and 20°C: 9 Watt
– Nominal current at 24V: 0.37 Ampere
The solenoid valve must audibly open, when voltage
is applied.
t Connect the solenoid valve plug to the control unit.
t Install burner (see 8.2).
Fig. 514
Fig. 515 Solenoid valve