Air conditioning system - function check

AP83.00-T-8352BAC

Air conditioning system - function check

20.12.04



Check

 Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near engine

Secure vehicle to prevent it from moving.
Wear closed and snug-fitting work clothes.
Do not grasp hot or rotating parts.

AS00.00-Z-0005-01A

1

Start air conditioning self-test

 To do this, press the reset (R) button with a pointed object.

During the self-test only the electric lines connected to the operating unit are checked for short-circuit or open-circuit.

 Call up and process faults found which are stored by fault code in the memory.



See Konvekta operating instructions.

2

Start engine

 For the function check on the air conditioning system, the coolant temperature must be at least 50 °C.

3

Press blower stage increase button (5)

 The current blower output is shown briefly in the display (17).The indicator lamp on the blower stage increase button (5) lights up.

4

Press blower stage increase button (13)

 The current blower output is shown briefly in the display (17).
The indicator lamp on the blower stage increase button (13) lights up.

5

Press automatic mode button (7)

 The indicator lamp on the automatic mode button (7) must light up.

Check refrigerant compressor

6

Set climate control for passenger compartment to lowest temperature that can be set

 To do this, press the temperature decrease button (2) repeatedly until the lowest temperature that can be set is reached.

 A function check on the cooling capacity of the air conditioning system is only possible if the outside temperature is above 17 °C.

7

Open rear engine flap

8

Carry out visual inspection of refrigerant compressor

 When the engine is running and the air conditioning is operating, the clutch hub (18) must rotate.

9

Close rear engine flap

Check condenser fans

 Danger!

Risk of death caused by falling from vehicle roof. Risk of injury to other persons caused by falling objects during work in roof area.

AS65.00-Z-0002-01A

10

Carry out visual inspection of condenser (arrows)

 When the engine is running and the air conditioning is operating, the condenser fans (arrows) must rotate.

Check cooling capacity of front box

11

Press temperature decrease button (12) repeatedly to close heating valve of front box

 The programmed opening angle of the heating valve is shown in the display (17).

 Example:

When the heating valve is 30% open, the number 3 is shown in the display (17).

12

Press AC mode button (15)

Only on front air conditioning code HO4

 The indicator lamp on the AC mode button (15) must light up.

13

Hold the sensor of the temperature measuring instrument in the air flow of the driver area ventilation and ascertain the temperature of the air flowing out



 On vehicles with front air conditioning code HO4:
The temperature of the air which is flowing out after approx. 5 minutes of operation must be distinctly lower than the outside temperature.

 On vehicles without front air conditioning code HO4:
The temperature of the air which is flowing out after approx. 5 minutes of operation must correspond to the outside temperature.



*WH58.30-Z-1002-08A

14

Press AC mode button (15)

Only on front air conditioning code HO4

 The indicator lamp on the AC mode button (15) must not light up.

Check air recirculation flap of front box

15

Hold a sheet of paper to the grille (19) and press the air recirculation mode button (16) alternately

 The indicator lamp on the air recirculation mode button (16) lights up when air recirculation is operating.

Air recirculation mode:

 The paper must be suctioned.

Fresh air mode:

 The paper must not be suctioned.

Check front box radial fans

16

Press blower stage increase button (13) repeatedly until the highest blower stage is reached

 The indicator lamp on the blower stage increase button (13) must light up.

The current blower stage is also shown briefly in the display (17).

 The blower capacity in the driver area must increase significantly.

Check front box heat output

17

Press temperature increase button (11) repeatedly to open heating valve of front box

 The programmed opening angle of the heating valve is shown in the display (17).

 Example:

When the heating valve is 30% open, the number 3 is shown in the display (17).

18

Hold the sensor of the temperature measuring instrument in the air flow of the driver area ventilation and measure the temperature of the air flowing out

 The temperature of the air flowing out increases, the larger the opening angle of the heating valve is.



*WH58.30-Z-1002-08A

Check cooling capacity in passenger compartment

19

Hold the sensor of the temperature measuring instrument in the air flow at the air nozzles (22) and measure the temperature of the air flowing out

 The temperature of the air which flows out after approx. 5 minutes of operation must be distinctly lower than the outside temperature.

If necessary check the air filters for contamination and/or check the air conditioning system for leaks:



Cleaning passenger compartment air filter

AP83.30-T-8334BAC



Inspect the refrigeration circuit for leaks.

AR83.30-T-1209-01C



*WH58.30-Z-1002-08A

Check passenger compartment recirculated air flaps

20

Remove air recirculation filter for passenger compartment ventilation

AP83.30-T-8338BAC

21

Press air recirculation mode button (10) to set ventilation in passenger compartment to air recirculation mode

 The indicator lamp on the air recirculation mode button (10) must light up.

22

Check position of air flaps (20)

 The air flaps (20) must be open.

23

Press air recirculation mode button (10) to set ventilation in passenger compartment to fresh air mode

 The indicator lamp on the air recirculation mode button (10) must not light up.

24

Check position of air flaps (20)

 The air flaps (20) must be closed.

Check passenger compartment radial fans

25

Press blower stage increase button (5) repeatedly until the highest blower stage is reached

 The indicator lamp on the blower stage increase button (5) must light up.

The current blower stage is also shown briefly in the display (17).

 The blower capacity must increase significantly.

26

Close all open air nozzles (22) above seats in passenger compartment

27

Open one air nozzle (22) on the left and right side of the vehicle in the passenger compartment

 Compare the air flows on the left and right side of the vehicle to each other.

 If the air flows are different:



Check function of the radial fans on the weak side.

Check passenger compartment roof heater

28

Set climate control for passenger compartment to highest temperature that can be set

 Press the temperature increase button (1) repeatedly until the highest temperature that can be set is reached.

29

Hold the sensor of the temperature measuring instrument in the air flow at the air nozzles (22) and measure the temperature of the air flowing out

 Warm air must come out of the air nozzles (22) on the left and right side of the vehicle after approx. 5 minutes.



*WH58.30-Z-1002-08A

Check convectors

30

The convectors (21) on the left and right side of the vehicle must warm up after a certain period of time

As of an outside temperature of above
24 °C the heating valve of the convectors (21) is taken out of operation by the control unit.

If the outside temperature is above 24 °C: 

 Cool the outside temperature sensor (B233) using suitable means.

31

Turn off engine

Number

Designation

WH58.30-Z-1002-08A

Digital temperature measuring instrument (measuring range -20° to +70°)