Function Checks; Basics; Check And Set Co₂ In Exhaust Gas - Webasto Thermo Top Pro 120 Workshop Manual

7 | Function checks

7 Function checks
7.1

Basics

NOTE
Continue to follow the warnings and information
provided in the operating- and Installation instructions.
7.1.1 Required test and measuring equipment
l Digital multimeter:
for measuring electrical resistance [ohms], electrical con-
tinuity 0.1 ohms test current < 5 mA
l Suitable voltage source
l Charged vehicle battery
l PC / Laptop
l Diagnostic adapter including Webasto Thermo Test soft-
ware for displaying the fault code memory, operating data,
control unit information. See chapter 6.1.1, "Diagnostics
with Webasto Thermo Test" on page 15.
l Pressure measuring device with fuel nozzle adapter
l CO measuring device:
2
Minimum specifications of CO
Resolution
CO 10 ppm
CO 0.1%
2
NOTE
Technical data refer to an ambient temperature of
20 °C, an air pressure of 1013 hPa.
7.1.2 Function check in the vehicle
NOTE
The heater switches first on the vehicle fan when the
coolant reaches a temperature of 30 °C.
Check the following points:
1. Vehicle settings
– Set the fan and temperature such that maximum heat is
provided in the vehicle (fan speed high, temperature
maximum, flap position).
– Check the coolant circuit and bleed it in accordance with
the vehicle manufacturer's regulations
– Test and bleed fuel system.
2. Heater settings
– Switch on the heater at the control element.
– Check heating action. Run the heater in combustion
mode. Check heating effect on the outflow nozzles of
the vehicle blower.
– Check the heater for leaks between the burner head and
the heat exchanger (visual inspection of the rough
quantity of the leak).
– Switch off the heater again at the control element.
24 / 49
-measuring device:
2
Precision Division
±5% 0-2000 ppm
±5% 0-16%
7.2 Check and set CO₂ in exhaust gas
NOTE
After repairing the heater it will be necessary to check
the CO setting.
2
It is recommended to check or reset the CO
after replacing the burner unit, the fan or the control
unit.
CO data: see chapter 11, "Technical data" on page 48.
2
It is permitted to change the factory-set level of combustion air
by amending the CO setting using the Webasto Thermo Test
2
PC Diagnostics.
7.2.1 Check CO₂ in exhaust gas
The heater should be in combustion mode to test the fuel val-
ues.
Maximum heat dissipation must be ensured so that the coolant
temperature remains as low as possible and several minutes in
combustion mode (approx. 5-10 minutes) are possible for the
test.
Procedure:
1. Switch on the heater
2. Read CO value after >5 minutes in combustion mode
2
Check the following values (see instructions to that effect at
chapter 11, "Technical data" on page 48):
CO in exhaust gas, CO and soot number as per Bacharach
2
7.2.2 Set CO₂ in exhaust gas
NOTE
The heater features automatic altitude compensation.
NOTE
Increase the speed of drive motor => measured CO
level must drop
Decrease the speed of drive motor => measured CO
level must increase
NOTE
The CO setting can only be carried out with Webasto
2
Thermo Test (WTT).
1. Connect the WTT (see chapter 6.1.1, "Diagnostics with
Webasto Thermo Test" on page 15).
2. Select the CO setting.
2
The heater starts automatically. The heater is operated in
CO setting mode, which is exclusively used for the CO
2
ting.
3. Correction of the CO
2
ments of 100 rev/min.
4. Position the CO measuring device in the exhaust system
2
branch of the heater according to the manufacturer's spe-
cifications. For measurement values, see CO
Chapter 11 .
NOTE
Enabling the setting function accepts the CO
9039412C Workshop manual TTP 120 _ 150
content
2
setting is recommended in incre-
data in
2
2
2
2
set-
2
value.