Malfunctions And Troubleshooting - Webasto Thermo Pro 90 Series Service Installations

Thermo Pro 90
5

Malfunctions and troubleshooting

General information
This chapter describes how to identify and remedy faults in
the Thermo Pro 90 heater.
ATTENTION
Troubleshooting assumes detailed knowledge of the design
and functional principle of the individual heater components
and must only be carried out by specifically trained personnel.
If in doubt, refer to Section 2 and 3 for information on how
the functions interact.
ATTENTION
Troubleshooting is generally restricted to locating faulty com-
ponents. The following potential sources of malfunction are
not taken into account as they should always be checked to
rule them out as the cause of fault:
• Corroded connector
• Loose plug connector
• Crimping defect at connector
• Corroded cables and fuses
• Corroded battery terminals
• Impermissibly high ambient temperature
Carry out a function check in the vehicle after rectifying each
fault.
5.1 Procedure in the case of fault,
malfunction and lock-out
ATTENTION
Always determine the cause of the lock-out first before recti-
fying the lock-out!
The control unit recognises faults in the heater as malfunc-
tions. Afterrunning may be initiated depending on the type
and severity of the fault. If afterrunning is initiated in the case
of fault, the heater remains in the lock-out state. A fault code
is also output after detecting a malfunction during the fault
switch-off.
The fault code is shown on the control element either by the
indicator lamp flashing of letter combination on the display
(depending on the type of control element).
The fault code assists the workshop or Webasto Technical
Service in determining the fault.
5 Malfunctions and troubleshooting
Select W-Bus under "Diagnostics" => "Device Selection" in
Webasto Thermo Test PC Diagnostics. It is recommended to
print out the operating and fault data as well as the extended
fault conditions.
5.1.1 Fault code output at the control element
• Control element (On/Off)
On control elements without a display (analogue), the fault
code is indicated in the form of a flash pulse.
Error code output:
After 5 fast flash pulses, the fault code is output by a sequence
of long flash pulses. The long flash pulses must be counted.
This number (fault code) provides information for the work-
shop about the type of heater malfunction.
• MultiControl / SmartControl element
In the case of control elements with a display (analogue or W-
bus), the malfunction is shown on the display in the form of a
fault code.
Error code output:
The fault code is indicated by a letter (F) followed by a 2-digit
combination (FXX).
• See Chapter "5.5 Fault code table (fault codes, flash
codes)" on page 503.
• The fault code for the heater begins with F (FXX). Other
fault codes do not stem from the heater (e.g. TXX for
MultiControl/SmartControl, see MultiControl/
SmartControl installation instructions).
5.2 Cause of malfunctions
A malfunction is caused when there is one or more faults
occur. Possible faults are:
Overvoltage / Undervoltage,
– malfunctions of all components, e.g. due to short-circuit
or break,
– overheating of heater,
– impermissible exhaust temperature,
– unsuccessful starts,
– flame failure.
NOTE
NOTE
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