Valeo Thermo E+ 120 - Page 37

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Thermo E+ 120/200/320 5 Troubleshooting
5.6.7 Electronic ignition unit inspection
For electronic ignition unit description, see 3.1.5.
No voltage of any kind or duration may be applied to
the ignition unit for test purposes. It may only be
operated and tested together with the associated
control device (component test of the DTT).
The function of the electronic ignition unit can only be
checked with the DTT diagnosis using the Component
test.
High voltage: The voltage received by the ignition
electrode is >13,000 Volt.During operation or testing
of the electronic ignition unit, the ignition electrode
may not be contacted by persons or items.
Inspection using the DTT diagnosis
• Remove burner (see 8.2).
• Inspect housing and ignition electrodes of the elec-
tronic ignition unit for damage.
• Connect the DTT diagnosis to the heater using the
adapter wiring harness (ref. to Operating Instructions
for the DTT diagnosis).
• Reconnect the heater with the vehicle electrical
system.
• Start DTT diagnosis, establish connection to the
heater and open the Component Test menu.
• In the Component Test menu, select the electronic
ignition unit and proceed according to the DTT
diagnosis instructions. Enter run time and start the
component test.
• Nominal condition:
Ignition sparks jump over at the ignition electrodes.
NOTES:
– How can it be determined whether the control
device or the electronic ignition unit (EIU) is defec-
tive?
If a resistance greater than 1 Ohm (primary
winding) is measured at the connector of the EIU,
a defect can be assumed (12 and 24V versions).
The EIU must be replaced. It is recommended to
replace it pairwise with the control device.
– For the error message "EIU interruption ..." or
"EIU short circuit ..." it is recommended to replace
the EIU pairwise with the control unit.
– The EIU electrodes must not be in contact with
adjacent assemblies. During the component test,
the spark may only originate between the electro-
des and not jump over to adjacent components.
– The error message: "EIU short circuit or no induc-
tion" may be the result of insufficient power supply
or defects in the electrical integration of the
heater.
– During the component test with the DTT, short-
term misfires are permissible in static air (without
fan). In the heater, the continuous sparking is sup-
ported and ensured by the air flow.
• After test completion, terminate DTT diagnosis as
needed.
• Disconnect the heater from the vehicle electrical
system (Observe 5.2 !).
Inadvertent operation of the removed burner can
cause severe burn injuries. If the burner and heat ex-
changer are separated, do not connect the temperatu-
re sensor to the control unit.
• Remove the DTT diagnosis adapter wiring harness as
required.
• Reinstall burner (see 8.2).
Explosion hazard!
Warning!
Risc of electric shock!
Warning!
Danger of severe
burn injuries!
Warning!