Aircon not working

[phillip]

My aircon hasn't seemed particularly cold just lately, so I've just been and had it serviced, but bro-in-law who did it tells me that it's not working. The pulley bolt is fine, so we put it on VCDS and in the Climate menu (?) it is coming up with error code 8 - external air temperature too low for aircon to operate. The ambient temp. on the dashboard is showing 15 degrees though, and although I have previously had an issue with this sensor and had it disconnected for the past 6 months, having re-fitted it this morning, it has worked okay for over an hour now, so I'm sure it's not this. (Did fit a replacement when it first started playing up, but that was just the same, i.e temp. display fluctuating anywhere between +/- 18 degrees).

Anyone got any ideas ??

[phillip]

Is there another air temp. sensor besides the one behind the front grille ?

[Jevpls]

I guess that there should be one somewhere inside. That air conditioner needs to know the temperature inside the car to know how should it operate. If that device isn't working properly then aircon can get wrong temperature measurements and work not properly. At least that seems pretty logic for me.

[pikpilot]

I guess that there should be one somewhere inside. That air conditioner needs to know the temperature inside the car to know how should it operate. If that device isn't working properly then aircon can get wrong temperature measurements and work not properly. At least that seems pretty logic for me.

 

I don't know the mk2's climate control enough but on the mk1 Octavia the climate control external temperature sensor is visible once you take out the pollen filter - and failures do occur. Again on the mk1 you can put the climate control into diagnostic mode by using a sequence of button presses as well as looking at what the sensor says is the temperature. It could probably be done on our cars too so perhaps someone can post details.

[phillip]

Anyone know if the mk2 is the same ??

[erindad]

March '15 was Silver '03 Elegance Estate 1.9 TDi

Posted Yesterday, 11:02

Jevpls, on 19 Jun 2015 - 10:12, said:

I guess that there should be one somewhere inside. That air conditioner needs to know the temperature inside the car to know how should it operate. If that device isn't working properly then aircon can get wrong temperature measurements and work not properly. At least that seems pretty logic for me.

 

I don't know the mk2's climate control enough but on the mk1 Octavia the climate control external temperature sensor is visible once you take out the pollen filter - and failures do occur. Again on the mk1 you can put the climate control into diagnostic mode by using a sequence of button presses as well as looking at what the sensor says is the temperature. It could probably be done on our cars too so perhaps someone can post details.

 

 

                         Softscoop posted a link on the 7th april on how to do it

[phillip]

Cheers Erindad...that tells me how to access the aircon diagnostics, but what should I be looking for in there ???

[erindad]

Hi Phillip,

 

try these,

 

 

19, Compressor Error Code,    should be Zero.  which means no reason for not working.

 

43, Refrigerant Pressure bar    ,should be  approx. = 16/17 bars  

 

50, I think refers to the HP switch

 

 there are others concerning the current draw of the compressor  No 47,

 

and  49,  compressor rpms.

 

Not sure about the last two numbers value.

 

Someone else will probably know more about them

 

This was something I copied a few years ago,

Channel, Displayed Value, Units

0, Program Number, Dig.

1, Interior Temperature, °C

2, Sunlight Intensity - Delayed 10, W/m^2

3, Sunlight Intensity - Instantaneous 10, W/m^2

4, Exterior Temperature - Delayed, °C

5, Exterior Temperature - Bumper, °C

6, Exterior Temperature - Fresh Air Inlet, °C

7, Vent Temperature - Footwell, °C

8, Vent Temperature - Dash, °C

9, Blower Voltage - Set Value 0.1, V

10, Blower Voltage - Actual 0.1, V

11, Temp.-Flap Set-Value, Dig.

12, Central-Flap Set-Value, Dig.

13, Recirc. Flap Set-Value, Dig.

14, Footwell/Defrost Flap Set-Value, Dig.

15, Motor Run Time, Hr.

16, Vehicle Speed, mph (km/h if not USA)

17, START_AP, Dig.

18, Recirc. Flap, Dig.

19, Compressor Error Code,

20, PI_STELLMAX Ausbl-Reg., Dig.

21, INT_STELL Ausbl-Reg., Dig.

22, Epsilon Ausbl-Reg., Dig.

23, Vent Temperature - Actual, °C

24, Vent Temperature - Set Value, °C

25, Temp. Flap (-) Limit, Dig.

26, RMP Temp. Flap, Dig.

27, Temp. Flap (+) Limit, Dig.

28, Central Flap (-) Limit, Dig.

29, RMP Central Flap, Dig.

30, Central Flap (+) Limit, Dig.

31, Recirc. Flap (-) Limit, Dig.

32, RMP Recirc. Flap, Dig.

33, Recirc. Flap (+) Limit, Dig.

34, Footwell/Defrost Flap (-) Limit, Dig.

35, RMP Footwell/Defrost Flap, Dig.

36, Footwell/Defrost Flap (+) Limit, Dig.

37, Standing Time, Min. (255 = No Data)

38, Compressor-PWM, Dig. (0-200)

39, Evaporator Temperature - Set Value, °C

40, Evaporator Temperature - Actual Value, °C

41, Evaporator - I-Stell, Dig.

42, Evaporator - Epsilon, Dig.

43, Refrigerant Pressure bar

44, BiLevel Mix/Dash Vent Flap, Dig.

45, Motor Temperature, °C

46, Compressor Current - Set Value, mA

47, Compressor Current - Actual Value, mA

48, Compressore Current - Maximum Value, mA

49, Compressor RPM, 100/min

50, Radiator Cooling Fan Control Signal, %

51, Windshield Wiper Mode, Dig. (0=Off, 1=Int, 2=On)

52, Fdk-Correction wrt Wiper Mode, Dig.

53, Blower Voltage Correction wrt Wiper Mode 0.1, V

54, Part Number

55, VW-Number

 

 

[phillip]

Thanks again Erindad, but those numbers don't tally with the ones on the link (or on my car)...

 

http://www.my-gti.com/224/volkswagen-climatronic-diagnostics

 

The main channel only goes up to 30 on the link and 31 on my car !

[phillip]

Just been into the diagnostic menu and have recorded the following values . (The car was at normal operating temp, on tickover, with the aircon on and the fan on 2 bars) :-

 

0. System Data Type

0 – 0 Program number Digital  0

0 – 1 ERL Left Digital 0

0 – 2 ERL Right Digital 0

0 – 3 Point being used Digital -04

0 – 4 Recirculating Automatic Digital 78 then 0 flashing

0 – 5 Stationary Heating Active Digital 0

0 – 6 Air Quality (7 = Fresh Air) Digital 0

0 – 7 Derived Digital 03

0 – 8 Country Acronym Digital 00

0 – 9 Sensor Zone Head °C

  

 1. UIF 

1 – 0 Internal Temperature °C  27.9

1 – 1 External Temperature °C 28.8

1 – 2 Temperatura? Piastrine? In? Platino? °C  -29.1

1 – 3 Correttore? Piastrine? In? Platino? °C  00.  1

1 – 4 Uif-Sonnenint? Digital  00

1 – 5 Sun Intensity Corrected °C  -00. 2

1 – 6 Correttore? Dinamico? °C  00.  8

1 – 7 Correttore? ricircolo? °C 00.  0

1 – 8 correttore? termico? °C 00.  0

1 – 9 Compensazione accensione UIF? °C 00.  0

  

 2. Sun Intensity Sensor Left 

2 – 0 Sun Intensity Not Corrected W/m2  08  0

2 – 1 Sun Intensity Corrected W/m2 10  0

2 – 2 Fan Correction W/m2   08  0

2 – 3 Value Digital  17  0

  

 3. Sun Intensity Sensor Right 

3 – 0 Sun Intensity Not Corrected W/m2  07  0

3 – 1 Sun Intensity Corrected W/m2  07  0

3 – 2 Fan Correction W/m2 07  0

3 – 3 Value Digital  16  7

  

 4 . External Temperature 

4 – 0 Temperature External °C 16.  0

4 – 1 Temperature External CANBUS °C 17.  0

4 – 2 Temperature Intake °C  63.  5

  

 5. Temperature Left Setpoint 

5 – 0 Temperature Output °C  03.  0

5 – 1 Difference between temp and temp setpoint °C  -25.  3

5 – 2 Regulator Setting (½%)  00  0

5 – 3 Pi-Stell-Max? (½%) 10  0

5 – 4 Defrost Digital  00  0

  

 6. Temperature Left Actual 

6 – 0 Temperature °C  28.  3

6 – 1 Footwell °C 28.  3

6 – 2 Vents °C  28.  3

  

 7. Temperature Right Setpoint 

7 – 0 Temperature Output °C 03.  0

7 – 1 Difference between temp and temp setpoint °C  -25.  3

7 – 2 Regulator Setting (½%) 00  0

7 – 3 Pi-Stell-Max? (½%) 10  0

7 – 4 Defrost Digital 00  0

  

 8. Temperature Right Actual 

8 – 0 Temperature °C  28.  3

8 – 1 Footwell °C 28.  6

8 – 2 Vents °C  28.  3

  

 9. Evaporator Temperature Setpoint

9 – 0 Evaporator temperature °C  02.  0

9 – 1 Difference between temp actual and temp Setpoint °C  -24.  0

9 – 2 Evaporator value settings 5mA/Dig 00  0

9 – 3 Sensor Sight  01

  

 10. Evaporator Temperature Actual

10 – 0 Evaporator Temperature °C  26.  0

10 – 1 Liquid refigerant pressure bar 06.  0

10 – 2 Liquid refigerant temperature °C  20.  0

  

 11. AC Compressor 

11 – 0 Power setpoint mA  82  0

11 – 1 Power actual mA   82  0

11 – 2 Power maximum mA  82  0

11 – 3 Compressor PWM Digital (0-200) 90.  0

11 – 4 Power offset compressor  01 1

11 – 5 Power value Digital 85  0

11 – 6 Compressor code  00

  

 12. Climate Control Fan 

12 – 0 Fan Setpoint Voltage V 04.  6

12 – 1 Manual regulation  05

12 – 2 Code anomaly  00

12 – 3 Reduction impeller V 00

12 – 4 Impeller offset 0.1V 00  0

  

 13. Temperature Air Vent Left 

13 – 0 Setpoint value %  00.  0

13 – 1 Setpoint temperature Digital 02  3

13 – 2 Actual Temperature Digital 02  7

13 – 3 Maximum Temperature Digital 21  7

13 – 4 Minimum Temperature Digital  03  2

  

 14. Temperature Air Vent Right 

14 – 0 Setpoint value % 00  0

14 – 1 Setpoint temperature Digital 02  3

14 – 2 Actual Temperature Digital  02  7

14 – 3 Maximum Temperature Digital 22 3

14 – 4 Minimum Temperature Digital 03  0

  

 15. Temperature Air Vent Diffuser

15 – 0 Setpoint value % 82.  5

15 – 1 Setpoint temperature Digital 19  6

15 – 2 Actual Temperature Digital 19  7

15 – 3 Maximum Temperature Digital 23  3

15 – 4 Minimum Temperature Digital 02  7

  

 16. Temperature Air Vent Defrost

16 – 0 Setpoint Value % 46.  5

16 – 1 Setpoint temperature Digital 12  3

16 – 2 Actual Temperature Digital 12  3

16 – 3 Maximum Temperature Digital 22  7

16 – 4 Minimum Temperature Digital  03  3

  

 17. Temperature Internal Recirculation

17 – 0 Setpoint Value % 00.  0

17 – 1 Setpoint temperature Digital 02  1

17 – 2 Actual Temperature Digital 02  5

17 – 3 Maximum Temperature Digital 23  2

17 – 4 Minimum Temperature Digital 02  7

  

 18. Temperature External Air 

18 – 0 Setpoint Value % 00.  0 flashing then 1

18 – 1 Setpoint temperature Digital 00  0

18 – 2 Actual Temperature Digital 00.  0

18 – 3 Maximum Temperature Digital 04  6

18 – 4 Minimum Temperature Digital 25  5

  

 19. Engine Data 

19 – 0 Vehicle Speed (kph) kph 00

19 – 1 Vehicle Speed (mph) mph 00

19 – 2 Engine Temperature °C 84

19 – 3 Engine speed RPM  07

19 – 4 AC compress speed RPM 09

  

 20. CANBUS Data 

20 – 0 Additional Heating 1=on 00

20 – 1 PTC Confirmation 1=on 00

20 – 2 Effective Power PTC A 00

20 – 3 Air requested from external % 00

20 – 4 External air percentage cooler % 00

20 – 5 Performance heating 1=no external provision 01

  

 21. Air Distribution 

21 – 0 Defrost % 46.  5

21 – 1 Face % 65. 0

21 – 2 Feet % 35 . 0

21 – 3 Air Vent Diffuser % 00.0

21 – 4 Recirculated % 00.0

21 – 5 Air Sensor % 82.  5

  

 22. Time 

22 – 0 Engine Off Time minutes 01  2

22 – 1 Engine Operating Time seconds 25  5

22 – 2 Operating Time with Ignition On seconds 25  5

22 – 3 ? 

22 – 4 ? 

22 – 5 ?  31.  2

  

 23. Special. Channel 

23 – 0 Inner Lighting Sensor Digital 00

23 – 1 Air Quality Sensor 

  

 24. Software Version 

24 – 0 Development State  01  0

24 – 1 Software Version  25  3

24 – 2 Type of Software 00  0 

24 – 3 Keep Frozen 0/1 – Diagnosis 00

24 – 4 Version K Matrix  28  9

24 – 5 EEP – Testflags   80h

24 – 6 Encryption Vag (2)  07  5

  

 25. Test Channels 

25 – 0 Channel 0  00  1

25 – 1 Channel 1  00  0

25 – 2 Channel 2  00  0

25 – 3 Channel 3  00  0

25 – 4 Channel 4  00  0

25 – 5 Channel 5  05  0

25 – 6 Channel 6  00  0

25 – 7 Channel 7  00  0

25 – 8 Channel 8  31  5

25 – 9 Channel 9  -26  6

  

 26. Parameters for inventory on crystals

26 – 0 Delay seconds 01

26 – 1 Step/udm? (Digital) Digital 01

26 – 2 Minimal Limit (Digital) Digital -99  9

26 – 3 Maximum Limit (Digital) Digital 99  9

26 – 4 Step/udm? HellaKit? 1=connected 00

  

 27. Direct Ventalation 

27 – 0 Setpoint Value %  --

27 – 1 Setpoint temperature Digital

27 – 2 Actual Temperature Digital

27 – 3 Maximum Temperature Digital

27 – 4 Minimum Temperature Digital

  

 28. Humdity 

28 – 0 Setpoint Humdity % --

28 – 1 Relative Humdity %

28 – 2 Temperatur Crystal WSS °C

28 – 3 Dewpoint temperature °C

28 – 4 Melting point °C

  

 29. Raw Humdity 

29 – 0 Tempertaure crystals corrected °C --

29 – 1 Tempertaure crystals uncorrected °C

29 – 2 Humdity Sensor %

29 – 3 Temperature sensor °C

29 – 4 Dewpoint temperature (measurement test) °C

29 – 5 Code anomaly 

  

 30. Humdity Values 

30 – 0 Thermophilic sensor value Digital --

30 – 1 Thermophilic sensor reference Digital

30 – 2 Moisture duration 10 to the power of -4 sec

30 – 3 Humdity reference temperature Digital

30 – 4 Humdity sensor %

30 – 5 Temperature sensor °C

30 – 6 Temperature sensor (uncorrected) °C

 

 

31-0       0dh

31-1       00

[erindad]

Looking at your list no 10 the refrigerant pressure seems be about 6 bar (last post I said 16/17 which is wrong.) 

 

You may have a different setup than one  the list refers to.

 

 Reading your first post again I now realise that you had it scanned with VCDS so I would go with those results.

 

  If the econ button is on then the A.C. will only cool to the outside air temp.

[softscoop]

 

 11. AC Compressor 

11 – 0 Power setpoint mA  82  0

11 – 1 Power actual mA   82  0

11 – 2 Power maximum mA  82  0

11 – 3 Compressor PWM Digital (0-200) 90.  0

11 – 4 Power offset compressor  01 1

11 – 5 Power value Digital 85  0

11 – 6 Compressor code  00

  

 

  

 19. Engine Data 

19 – 0 Vehicle Speed (kph) kph 00

19 – 1 Vehicle Speed (mph) mph 00

19 – 2 Engine Temperature °C 84

19 – 3 Engine speed RPM  07

19 – 4 AC compress speed RPM 09

  

 

 

 

I had pretty much the exact same figures on mine when I had it regassed, and it still wasn't cold.

 

After a diagnostic report from a specialist, the compressor was shown to be at fault.

[phillip]

Cheers guys...what's puzzling me though is the fact that the VCDS showed error "code 8 - external air temperature too low for aircon to operate", which tends to make me think it is an electronic issue rather than a mechanical one, plus the fact that the ambient temperature display on the dashboard has dropped to -18 degrees again this morning !!!

[meta55b]

Using the link to the golf site, I used it to check my pressure and it sits at about 5 1/2 / 6 bar if the aircon is on and off. I do get really cold air, do I have some sort of problem??.

[Jelibeli]

Cheers guys...what's puzzling me though is the fact that the VCDS showed error "code 8 - external air temperature too low for aircon to operate", which tends to make me think it is an electronic issue rather than a mechanical one, plus the fact that the ambient temperature display on the dashboard has dropped to -18 degrees again this morning !!!

I would have thought that an air temperature sensor would be cheaper than an a/c pump, so if it's easy to get at, just try fitting a new one and see what happens.

[phillip]

I have replaced the air temp sensor twice now (the one behind the fog light shroud), but it has made no difference whatsoever, but am led to believe that there may be another one somewhere (??), which may be the cause of the problem ? 

[meaty101]

Just wondered ( I'm no a/c expert ) if the pressure is reading low could it be a faulty pressure sensor. Mines coldish but i can't say I'm too impressed with it. I'll be changing mine soon although it looks like we've had our 3 days of summer here! !

[phillip]

Are you referring to this ?? ...

 

10 – 1 Liquid refigerant pressure bar 06.  0

 

If so, is 6 bar too low, and if it is, where do I find the pressure sensor ??

[meaty101]

I'm not clued up on aircon, mine is rubbish too so we're in the same boat here. You mentioned in your first post your brother in law had serviced the system but it wasn't very cold. Mine is ok and this may be quite normal for these but it's not freezing cold like i think it should be. If he's serviced it for you he will have regassed the system so i would have thought the pressure would be higher than the system says. It might be a faulty pressure sensor but you don't want to go down the route of throwing money at it blindly. I got into the climate settings yesterday following the link and mine was reading 12bar pressure and mine has just been regassed last week. A few people on here have mentioned poor air con temp and after changing the pressure sensor all was well again. So I'll be doing that soon as I'm fairly certain the compressor is fine.

[meaty101]

The pressure sensor is near the front of the engine bay next to the left hand cooling fan as you look in from the front. You'll see the black connector going to it. I tried taking a picture but its in a difficult place. A 17mm crow foot spanner is needed to remove it.

[erindad]

My aircon hasn't seemed particularly cold just lately, so I've just been and had it serviced, but bro-in-law who did it tells me that it's not working. The pulley bolt is fine, so we put it on VCDS and in the Climate menu (?) it is coming up with error code 8 - external air temperature too low for aircon to operate. The ambient temp. on the dashboard is showing 15 degrees though, and although I have previously had an issue with this sensor and had it disconnected for the past 6 months, having re-fitted it this morning, it has worked okay for over an hour now, so I'm sure it's not this. (Did fit a replacement when it first started playing up, but that was just the same, i.e temp. display fluctuating anywhere between +/- 18 degrees).

Anyone got any ideas ??

 

Hi Philip,

                I decided to check my octy this morning and did not get any error codes for    Address 08 HVAC.  When I went into the measuring blocks this is what I got.

 

 

  003   Air-conditioning operation information heating

  005   Compressor current; actual value 0.270 A

  006   Compressor current; specified value 0.260 A

  007   Compressor load 2.3 Nm

  008   Compressor shut-off condition; last Outside air temperature too low

  026   Engine speed 700 /min

  040   Interior temperature 23.7 °C

  067   Outside air temperature-MUX Temperatur 15.0 °C

  068   Outside air temperature internally calculated-MUX Temperatur 15.0 °C

  078   Refrigerant pressure-MUX Kaeltemitteldruck 6.4 bar

 

For a octy 2011.

 

  Now at 008 I have I think the same as you, but it is information code and not a fault code, and my A/C is working perfectly , OK  some people might think the pressure is down but when revved up it goes to approx. 9 bar before settling back down .

 

 Any fault codes with my VCDS are shown in red.  I think there may have been confusion about the meaning of the Fault Codes  and codes. 

[phillip]

Cheers guys.....meaty101, re the pressure sensor, I have taken a pic of what I think you are referring to (attached..hopefully !!), but when I undo it, will all the gas escape and then need refilling afterwards  ??

 

 

 

[phillip]

Erindad...just been and checked the pressure again at 10-1 and it stays around the 5.6 bar mark regardless of whether I rev the engine or not - albeit the engine is cold - but not as cold as the ambient temp. which is currently displaying as minus 17 degrees, so is this wayward temp. preventing the aircon from kicking in and the pressure increasing as you say it should ??

[meaty101]

Cheers guys.....meaty101, re the pressure sensor, I have taken a pic of what I think you are referring to (attached..hopefully !!), but when I undo it, will all the gas escape and then need refilling afterwards ??

Yes I'm certain that's the pressure sensor well it's what I'll be changing!! I've never changed one but apparently there is a valve that the sensor pushes onto and opens when tightened ( like a tyre valve ) so unless the valve is stuck open no gas should escape.

[phillip]

Cheers mate...will try changing that first...just need to go and get a 17mm crow foot spanner now !!!