Air conditioning system - function check

AP83.00-T-8352BAF

Air conditioning system - function check

3.2.05



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 engine

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

 When the engine is started the climate control switches on automatically and automatic temperature control starts in the passenger compartment.

 Pay attention to air conditioning operating manual where necessary.

Check refrigerant compressor

2

Call up and note current outside and interior temperatures

 Press the outside, interior temperature inquiry button (9) until the required information appears in the display (4).

A function check on the cooling capacity of the air conditioning system is only possible if the outside temperature is above 21 °C.

3

Set specified temperature for passenger compartment to lowest temperature that can be set

 Press the specified value decrease button (5) repeatedly until the lowest temperature that can be set is reached.

4

Open rear engine flap

5

Carry out visual inspection of refrigerant compressor

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

6

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

7

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 front box radial fans

8

Move blower stage rotary switch (2) in stages repeatedly until the highest blower stage is reached

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

Check air recirculation flap of front box

9

Hold a sheet of paper to the grille (19)

 Get an assistant to help if necessary.

10

Move the recirculated air, fresh air rotary switch (1) alternately to determine the air flow at the grille (19)



Air recirculation mode:

 The paper must be suctioned.

Fresh air mode:

 The paper must not be suctioned.

Check front box heat output

11

Turn temperature control rotary switch (3) to highest heat output setting

12

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

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



*WH58.30-Z-1002-08A

Check cooling capacity in passenger compartment

13

Hold the sensor of the temperature measuring instrument in the air flow at the air nozzles (22) and determine 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 interior air filters for contamination and/or check the air conditioning system for leaks:



Air conditioning - cleaning the air filter for passenger compartment ventilation

AP83.30-T-8334BAF



Inspect the refrigeration circuit for leaks.

AR83.30-T-1209-01C



*WH58.30-Z-1002-08A

Check passenger compartment recirculated air flaps

14

Remove air recirculation filter for passenger compartment ventilation

AP83.30-T-8338BAC

15

Check the position of the air flaps (20) for the ventilation in the passenger compartment

 If the automatic mode indicator lamp (11) lights up, the air flaps (20) are in the open position and thus in air recirculation mode.

16

Change position of air flaps (20)

 To change the position of the air flaps (20), the specified value increase button (10) or the specified value decrease button (5) must be pressed immediately after the air flap inquiry button (8) is pressed.

Air recirculation mode:

 The air flaps (20) are open and RECIRC is shown briefly in the display (4).

Fresh air mode:

 The air flaps (20) are closed and FRESH is shown briefly in the display (4).

17

Install air recirculation filter for passenger compartment ventilation

 Inspect air recirculation filter for contamination, clean if necessary.

AP83.30-T-8338BAC

Check passenger compartment radial fans

18

Press blower stage inquiry button (7) and call up current blower output

 The current blower stage is shown briefly in the display (4).

19

Press specified value increase button (10) or specified value decrease button (5) alternately to change blower output

 Press the specified value increase button (10) or specified value decrease button (5) immediately after pressing blower stage inquiry button (7) to change blower output of radial fans.

The blower output must increase or decrease noticeably.

20

Press specified value increase button (10) until highest blower output in passenger compartment is reached

 Press specified value increase button (10) immediately after pressing blower stage inquiry button (7).

21

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

22

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

23

Compare the air flows on the left and right side of the vehicle with each other

 If the power of the air flowing out is not the same:



Check function of the radial fans on the weak side.

Check passenger compartment roof heater

24

Set specified temperature in passenger compartment to highest heat output level

 Press the outside, interior temperature inquiry button (9) until SET appears in the display (4). Press the specified value increase button (10) repeatedly until the highest specified temperature is reached.

25

Press automatic mode button (6) and blower stage inquiry button (7) simultaneously to switch off air conditioning system

 VIPER OFF is shown in the display (4) when the air conditioning system is switched off.

26

Turn off engine

27

Start engine after approx. 1 minute waiting time

28

Ensure that specified temperature in passenger compartment is set to highest heat output setting

 Press the outside, interior temperature inquiry button (9) until SET appears in the display (4).

Set specified temperature to highest heat output setting if necessary.

29

Hold the sensor of the temperature measuring instrument in the air flow of the passenger compartment ventilation and ascertain 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

Hold sensor of temperature measuring instrument to convectors (21) and determine temperature

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



*WH58.30-Z-1002-08A

31

Press automatic mode button (6) and blower stage inquiry button (7) simultaneously to switch off air conditioning system

 VIPER OFF is shown in the display (4) when the air conditioning system is switched off.

32

Turn off engine

Number

Designation

WH58.30-Z-1002-08A

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