Webasto Air Top Evo 55 User manual

Air Heaters
Fault Codes / Troubleshooting
Air Top Evo 55
Air Top Evo 55 B (Petrol)
Air Top Evo 55 D (Diesel)
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Troubleshooting Air Top Evo 40 / Air Top Evo 55
501
5 Troubleshooting
5.1 General information
If a malfunction occurs, a flashing code is displayed on the
operating indicator or a fault code F .. on the combination
timer.
In addition, the heater can be checked using a personal com-
puter (see Webasto PC Thermo Test PC Diagnosis operating
manual).
IMPORTANT
Troubleshooting work demands precise knowledge of the
structure and theory of operation of the various components
and must be carried out by trained personnel only. The func-
tional relationships are described in Chapter 2 and 3.
IMPORTANT
The troubleshooting guide is restricted to the localisation of
defective components.
The following fault causes should always be checked or a
fault should be excluded for the following reasons:
• Corrosion on connector
• Loose connection on connector
• Poor crimp contacts on plugs
• Corrosion on lines and fuses
• Corrosion on battery terminals
If you wish to check individual components, the electrical
plug connectors on the control unit must be disconnected.
Conduct a function test in the vehicle after rectifying each
fault.
A direct operation of the individual components (with volt-
age) is not permitted.
5.2 General error symptoms
The following table (Fig. 501) lists possible fault symptoms.
Error symptom Possible cause Remedy
Heater cuts out automatically No combustion after starting and restarting
Operating display flashes
Switch heater off and then on again
Flame extinguishes during operation
Operating display flashes
Switch heater off and then on again
Heater overheated
Operating display flashes
Check the hot air guide for free passage, al-
low the heater to cool down, then briefly
switch the heater off and then on again
Vehicle voltage too low
Operating display flashes
Charge battery
Switch heater off and then on again
Heater emits black smoke Combustion air and/or exhaust system
blocked
Check that the combustion air and exhaust
systems are clear
Fig. 501 General error symptoms
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Air Top Evo 40 / Air Top Evo 55 Troubleshooting
502
5.3 Error symptoms during function
The following table (Fig. 502) lists the possible error symp-
toms in the order in which they may occur during operation.
In the event of a fault, the error is to be located using this ta-
ble and rectified. It is important that the error symptom is cor-
rectly identified.
If the error symptom is not included in this table or if the fault
is not found under the specific error symptom heading, in an
emergency you can contact our technicians on our service
hotline.
NOTE
Every fault is indicated by the flashing LED on the control el-
ement after the slow down time has finished. If the other
components are OK, a defective control unit may be the
cause of all the faults.
There are states which are equivalent to faults.
Error symptom Occurrence Possible causes
No start and no illumination of the LED
on the control element
immediate Incorrect cabling, defective fuse
No start but LED is lit immediate The unit immediately goes into a control break when
switched on; the control break speed is 0 rpm when an
external temperature sensor is used.
Fig. 502 Error symptoms during function
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Troubleshooting Air Top Evo 40 / Air Top Evo 55
503
5.4 Fault code displayed in control element
If serious malfunctions, such as overheating or failure to start,
occur with increasing frequency, then the heater is
permanently locked out and can only be returned to
operation following repairs by Webasto-trained
professionals.
When equipped with a combination timer, a fault code
output appears on the display after a malfunction occurs until
the heater malfunction has been eliminated.
In case of equipment with a rotary selector or an Air Top Evo
Multi Control the fault code is displayed by means of a
flashing operating indicator after a malfunction occurs .
After five short signals, the long flashing pulses are counted.
The flashing pulses match the number in the table below (e.g.
F 04 = 4 long flashing pulses).
NOTE
For equipment with combination timer:
Fault codes F 01 to max. F 15 are displayed.
After this the faults are displayed with "- -".
Fault
code
Fault (group) Additional information during PC di-
agnostic
Troubleshooting
F 00 Control unit defective/
heater lock-out/
internal room temperature sensor
defective
01 Control unit error
81 EOL checksum error
11 Incorrectly coded control unit or incorrect
heater (fuel type) installed (the heater will not
work if this error occurs)
91 Neutrally coded or disabled control unit
(the heater will not work if this error occurs)
92 Maintain command failed (no operation if
fault occurs)
18 Customer bus defective
Replace control unit
07 Heater lock-out active Delete heater lock-out:
Switch on unit and remove fuse.
Reinstall fuse after more than 2 s and switch
on unit again
F 01 No start/no flame formation 02 Even after the restart, no flame has
formed
82 No start in test
83 Maximum feed rate exceeded
Check fuel supply
(tank empty, lines blocked).
Check exhaust temperature sensor for
deposits from outside through exhaust fitting
and clean carefully if necessary.
Check evaporator mount and replace if
necessary.
F02 Flameabort 03 The flame has gone out during operation
and has not reformed after a restart attempt
Check fuel supply
(tank empty, lines blocked).
Check exhaust temperature sensor for
deposits from outside through exhaust fitting
and clean carefully if necessary.
Check evaporator mount and replace if
necessary.
F 03 Undervoltage or overvoltage 84 The voltage was less than 10.5 V or 20.5
V for longer than 20 seconds
04 The voltage was more than 16 V or 32 V
for longer than 6 seconds
F 04 Premature flame detection 05 The exhaust temperature sensor
recognised a flame before combustion had
started
Check exhaust temperature sensor and
replace if necessary.
Fig. 503 Faults and error remedies (Page 1 of 2)
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Air Top Evo 40 / Air Top Evo 55 Troubleshooting
504
F 05 Not available
F 06 Not available
F 07 Fuel pump defective 88 Open circuit in fuel pump Check electrical wiring and fuel pump and
replace if necessary
08 Short circuit in fuel pump
F 08 Open circuit/short circuit/
overloading/blockage in drive motor
09 Short circuit in drive motor
89 Open circuit in drive motor
15 Blocking guard in drive motor
95 Overload protection in drive motor
Eliminate cause of blockage/sluggishness
Check magnets of heating air fan and replace
drive unit (drive motor with combustion and
heating air fan) if necessary
F 09 Glow plug defective 19 Short circuit in glow plug
99 Open circuit in glow plug
Check glow plug and replace if necessary.
F 10 Overheating 06 Heater overheated - blow-out
temperature sensor
5B Heater overheated - PCBs - temperature
sensor
17 Temperature gradient exceeded - blow-
out temperature sensor
5C Temperature gradient exceeded - PCBs -
temperature sensor
Find and eliminate cause of overheating in
hot air guide.
Possible causes:
Pressure loss too high, line kinked, air outlet
closed, soiling of blow-out temperature
sensor
F 11 Not available
F 12 Not available
F 13 Not available
F 14 Blow-out temperature sensor
defective
1B Short circuit in blow-out temperature
sensor
AB Open circuit in blow-out temperature
sensor
Check blow-out temperature sensor and
replace if necessary.
F 15 Not available
F 16 Exhaust temperature exceeded 4F Upper limit of exhaust temperature
exceeded
Check free through-flow of combustion air
and exhaust system, check CO2setting, clean
soot from heat exchanger if necessary
F 17 Exhaust gas temperature sensor
defective
1A Short circuit to ground in exhaust
temperature sensor
9A Open circuit in exhaust temperature
sensor
Replace exhaust temperature sensor
F 18 Setpoint generator defective 9B Open circuit or short circuit to +Ub in
setpoint generator
Check wiring and replace control element if
necessary
F 19 Plausibility of sensors incorrect 93 Plausibility check not passed Check exhaust temperature sensor/blow-out
temperature sensor for plausibility and
replace defective sensor
Fault
code
Fault (group) Additional information during PC di-
agnostic
Troubleshooting
Fig. 503 Faults and error remedies (Page 2 of 2)
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Troubleshooting Air Top Evo 40 / Air Top Evo 55
505
5.5 Maintenance display in control element
The maintenance signal is displayed when an operating
period of more than 3,000 operating hours has been reached
or the heater is in a restricted operating mode.
In case of restricted operation, either the automatic altitude
adjustment or the external room temperature sensor
(optional) may be defective. The heater can continue to be
operated, however with a considerable reduction in comfort
in some cases.
The heater should be inspected by trained professionals as
soon as possible.
The maintenance signal is displayed with equipment with a
rotary selector or an Air Top Evo Multi Control (MC04) by
means of flashing of the operating indicator for 60 seconds
each time the heater is started. Flashing signal 1 second on,
1 second off.
With equipment with combination timer, "- -" appears on the
display.
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