Valeo Thermo H 160 Workshop Manual page 18

Thermo H
Malfunction interlock release
The malfunction interlock is released when the heater is
switched off.
After that it will be immediately ready for operation.
Deleting the error using the diagnosis
The detected error is stored in the error memory and can
be read out using the DTT diagnosis.
It is possible to delete the stored error using the DTT
diagnosis.
4.3.6.2 Heater interlock
The heater interlock overrides the standard
malfunction interlock.
If the heater interlock is active, neither start nor run-down
are executed after switching the heater on again.
Prior to restarting the heater troubleshooting must be
performed by personnel trained by Valeo in order to
identify and remedy the cause.
After that the heater interlock can be released (see
below).
Here it is differentiated between interlocks caused by
overheating and interlocks caused by other errors.
NOTE:
If malfunctions occur during switching-on or during the
start process prior to ignition, the heater will be switched
off without run-down.
The heater is in heater interlock state.
The burner motor stops immediately or does not start.
Besides that a run-down between 30 seconds and up to 120
seconds is performed depending on error type and timing.
Subsequently the heater status is switched to heater interlock.
If the circulating pump is externally actuated, it will
continue operating.
Heater interlock causes:
• Short circuit and/or interruption of electrical
components:
– Solenoid valve
– Flame detector
– Overheating protection
– Disconnection of the water temperature sensor
(overheat protection / temperature sensor)
• The flame is not expired within 30 seconds after the
run-down was started (Burner motor stops).
• Overheating protection triggered.
• Control unit error
• Repeated malfunctions
• Repeated flame interruptions
4 Functions of the heater
Heater interlock release
ATTENTION:
A distinction is made between heaters with standard
control (pre-selection timer, switch, etc.) and heaters
controlled via a CAN bus.
Heaters with standard control
To release the heater interlock the heater must be discon-
nected one time from the vehicle electrical system.
Heater interlock release procedure:
1. Remedy the cause of the heater interlock.
2. Switch on the interlocked heater.
3. Disconnect the switched on heater from the vehicle
electrical system.
4. Reconnect the switched on heater to the vehicle
electrical system.
NOTE:
The heater starts after reconnection to the vehicle electri-
cal system automatically.
The heater can be switched off during initial cycle.
Heater interlock release using the DTT diagnosis:
1. Connect the heater with the DTT diagnosis and read
out the error memory.
2. Correct the cause of the heater interlock.
3. Disconnect the heater from the vehicle electrical
system.
4. Reconnect the heater to the vehicle electrical system.
5. Clear the error memory using the DTT diagnosis.
Heaters with control via CAN bus
Heater interlock release by pulling the fuse:
ATTENTION:
It is not allowed to disconnect the heater from the
vehicle mains by pulling the heater connector under
power.
1. Disconnect the switched-on and interlocked heater
from the vehicle electrical system for > 10 seconds by
pulling the vehicle-mounted heater fuse (F1).
2. Remedy the cause of the heater interlock.
3. Connect the switched-on heater to the vehicle elec-
trical system by inserting the vehicle-mounted fuse
(F1).
4. Disconnect the switched-on heater again from the
vehicle electrical system for > 10 seconds
Heater interlock release using the DTT diagnosis:
407