The sun comes out and so the Air-con stops working!

 

I’ve no tools anymore and have physical problems now so I can’t do serious investigation work myself but would like to understanding the fault before paying for the fix if anyone can help.

 

Air-con was working before I got the car washed with pressure hoses (perhaps relevant). The day after no air-con!  Had my Octavia MkII (2007) from new; it’s an Elegance 1.9 TDI (Climatronic -E87- with Climatronic control unit -J255). I keep the AC on Econ off all year.

H@lf*rds air con guy spent quite a while on it this morning. He said all the major components are fine but couldn’t solve the problem and suggests an Auto Electrician:-

·         Gas pressure fine – doesn’t need regassing,

·         No leaks

·         Compressor fine

·         Condenser fine

 

I read https://www.briskoda.net/forums/topic/360099-aircon-not-working/ and so took the following from the control menu. The car had been running for 20 mins in the ‘blistering UK’ sun before I parked up and took readings.

 

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 -03.0

0 – 4 Recirculating Automatic Digital 0

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  38.0

1 – 1 External Temperature °C 38.0

1 – 2 Temperatura? Piastrine? In? Platino? °C  -38.0

1 – 3 Correttore? Piastrine? In? Platino? °C  0.4

1 – 4 Uif-Sonnenint? Digital  0.3

1 – 5 Sun Intensity Corrected °C  -0.6

1 – 6 Correttore? Dinamico? °C  0

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  12

2 – 1 Sun Intensity Corrected W/m2 15

2 – 2 Fan Correction W/m2   12

2 – 3 Value Digital  18

  

 3. Sun Intensity Sensor Right 

3 – 0 Sun Intensity Not Corrected W/m2  35

3 – 1 Sun Intensity Corrected W/m2  37

3 – 2 Fan Correction W/m2 36

3 – 3 Value Digital  27

  

 4 . External Temperature 

4 – 0 Temperature External °C 20

4 – 1 Temperature External CANBUS °C 25

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  -31.5

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  35.5

6 – 1 Footwell °C 37.5

6 – 2 Vents °C  35.5

  

 7. Temperature Right Setpoint 

7 – 0 Temperature Output °C 03.  0

7 – 1 Difference between temp and temp setpoint °C  -32.3

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  35.6

8 – 1 Footwell °C 35.5

8 – 2 Vents °C  35.6

  

 9. Evaporator Temperature Setpoint

9 – 0 Evaporator temperature °C  02.  0

9 – 1 Difference between temp actual and temp Setpoint °C  -31.6

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

9 – 3 Sensor Sight  01

  

 10. Evaporator Temperature Actual

10 – 0 Evaporator Temperature °C  33.6

10 – 1 Liquid refrigerant pressure bar 07.6

10 – 2 Liquid refrigerant 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) 92.0

11 – 4 Power offset compressor  9.2

11 – 5 Power value Digital 4.8

11 – 6 Compressor code  00

  

 12. Climate Control Fan 

12 – 0 Fan Setpoint Voltage V 06.  4

12 – 1 Manual regulation  02

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 2 .5

13 – 2 Actual Temperature Digital 3.0

13 – 3 Maximum Temperature Digital 22.5

13 – 4 Minimum Temperature Digital  2.9

  

 14. Temperature Air Vent Right 

14 – 0 Setpoint value % 00  0

14 – 1 Setpoint temperature Digital 2.1

14 – 2 Actual Temperature Digital  02.7

14 – 3 Maximum Temperature Digital 22.3

14 – 4 Minimum Temperature Digital 2.5

  

 15. Temperature Air Vent Diffuser

15 – 0 Setpoint value % 95.0

15 – 1 Setpoint temperature Digital 22.2

15 – 2 Actual Temperature Digital 22.3

15 – 3 Maximum Temperature Digital 23.3

15 – 4 Minimum Temperature Digital 02.7

  

 16. Temperature Air Vent Defrost

16 – 0 Setpoint Value % 0

16 – 1 Setpoint temperature Digital 2.5

16 – 2 Actual Temperature Digital 3.0

16 – 3 Maximum Temperature Digital 22.7

16 – 4 Minimum Temperature Digital  2.9

  

 17. Temperature Internal Recirculation

17 – 0 Setpoint Value % 00. 0 flashing then 1

17 – 1 Setpoint temperature Digital 21.8

17 – 2 Actual Temperature Digital 21.2

17 – 3 Maximum Temperature Digital 21.4

17 – 4 Minimum Temperature Digital 4.8

  

 18. Temperature External Air 

18 – 0 Setpoint Value % 0

18 – 1 Setpoint temperature Digital 2.6

18 – 2 Actual Temperature Digital 2.9

18 – 3 Maximum Temperature Digital 23.2

18 – 4 Minimum Temperature Digital 2.9

  

 19. Engine Data 

19 – 0 Vehicle Speed (kph) kph 00

19 – 1 Vehicle Speed (mph) mph 00

19 – 2 Engine Temperature °C 82

19 – 3 Engine speed RPM  08

19 – 4 AC compress speed RPM 10

  

 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 % 10

20 – 5 Performance heating 1=no external provision 01

  

 21. Air Distribution 

21 – 0 Defrost % 0

21 – 1 Face % 0 flashing then 1

21 – 2 Feet % 0

21 – 3 Air Vent Diffuser % 00.0

21 – 4 Recirculated % 0 flashing then 1

21 – 5 Air Sensor % 0 flashing then 1

  

 22. Time 

22 – 0 Engine Off Time minutes 1.3

22 – 1 Engine Operating Time seconds 25.5

22 – 2 Operating Time with Ignition On seconds 25.5

 

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  18.2

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)  17.7

  

 25. Test Channels 

25 – 0 Channel 0  00  0

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  00  0

25 – 9 Channel 9  00  0

  

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 %  --

  

 28. Humdity 

28 – 0 Setpoint Humdity % --

 

29. Raw Humdity 

29 – 0 Tempertaure crystals corrected °C --

 

 30. Humidity Values 

30 – 0 Thermophilic sensor value Digital –

 

 

31-0    0dh

31-1   01

Edited 15 May, 20188 yr by m0ezp

Air-con still not cooling air and I'm no-where near understanding why. I've taken readings from the Climatronic onboard diagnostics and attached them - they were taken after the engine was up to temperature on three successive days which usefully were hot, warm and cool :-) Not sure if the data gives any clues?

 

I found the 40A fuse #40 marked as " Air blower for heating and air conditioning " was missing - I've stuck a new fuse in. It's not blown but air-con still not cold.

 

Also, should the smaller fan at the back of the radiator be running?

 

 

Aircon not working.pdf

TBH, I wouldn't let Halfords change more then the tyres and battery!

Go to an air-con specialist or a VW/Skoda specialist who does a/c too. I think you will find a better service from them, even though it will cost a bit more. In relation to a/c climatronic, I have a Fabia which had fan issues, dash out, new fan quite a few quid but on driving off, a/c freezing my nips off, I thought it was money well spent. 

Thanks mrgf. I'm with you for Halfords on tyres and battery. They were the nearest and easiest option although told me nowt! :-D Nearest proper VW/Skoda service is quoting £90 for diagnostics but can't book me in til week after next when I'm away in my warm car!

 

Sounds to me as your N280 valve has gone, could be coincidence, but they do go, had mine go 2 years ago, compressor and condenser later all back running again.

 

Looking at the data you supplied, have a look at the comp shut off code 0.0, that means the HVAC ECU and it is an ECU, is telling the N280 valve to open, but they do jam shut, mine did, so had to replace it, dealer wanted thick end of £1500, so did it my self handy being a tech.

 

Hope this helps,

 

Trev

Thanks Trev, that's great. You've given me hope and its good to understand the logic. Luckily the valve top is easy to access so I jiggled about with its connector (see attached photo); a long shot but just in case the connection was a bit iffy - it didn't change anything sadly.

 

I've just run the car around to reach engine temp with the Climatronic set to LO and interior fan on full and then had a look at the smaller fan on the back of the radiator but it wasn't not moving. I'm presuming that the smaller fan is what the diagnostic section 12 is all about and that 12-2 listed as "Code anomaly" is where an error code would show? Wouldn't you expect that when the ECU is 'calling for cooling', so to speak, it would start up the smaller fan on the radiator? 

 

btw I've booked the car in to see an independent auto electrician on Monday who say's he's got all the VAG gear to determine the problem. I'm not in a position to do the work myself unfortunately so I'm trying to understand what's going on and hopefully won't get the £silly quote scenario.

 

David

so are we talking halfords word as given that the pressure is good?

 

i found on a discovery you could pressureise the system when the engine wasnt running but the moment you started it the pressure would drop.

turned out that is where the hole was.

 

simalarly on the octavia i gased it when the engine was running and it pressurised but then dropped off.

plugged in some UV die and found my problem, a small hole in the rad, but too big for the sealer to fix.

done a tempary fix with checmical metal with the aim to replace it when i have some more time.

i guess my question is, does it maintain pressure and does the RAD fan kick in?

Interesting Little Grey. Thanks for your thoughts and they give me more to think about

 

I don't know what Halfords really did. They said they'd tested the pressure, but as you say, perhaps when the engine wasn't running. They said they'd checked for leaks and didn't find any - if they did I'd have thought they'd have to have done something like you did - but did they. They said the compressor and condenser were okay - I've read about compressors breaking internally but looking fine on the outside so don't know how far they took that.

 

In many ways, I wish I could turn air-con off for the timebeing and get fresh air from the outside like in the olden days but if I switch it off it seems to turn the external inlet off as far as I can tell.

just spotted your ps

 

I did monitor the pressure via onboard diagnostics (10 – 1 Liquid refrigerant pressure bar ). It seemed to start at over 4 bar and I've seen it close to 8 bar.

 

I'm not seeing the rad fan kick-in which has been nagging me a bit. I don't know if fan codes are shown in (12 – 2 Code anomaly  ) - that's always zero.

i just grabbed my recharge tool (same as what halfords use) and it suggests that it should be between 25 and 40psi

or 172-275 kpa.

 

i have no idea what the conversion is to bar.

 

but i found that the system would only activate over about 20 psi.

 

-

 

i think i should get a vag cable. they look really handy bits of kit.

The green section on the meter suggests gas pressure is okay I think (25psi = 1.72bar, 40psi = 2.75bar). I've only ever checked with the engine running which increases the pressure so hopefully my readings are ok.

 

I've looked at the evaporator data and that's showing 10C on a hot day, 7C on a cool day which I'm guessing means its doing something useful....just not sharing it with me!

ha, how helpful of it!

 

i have been doing research on VDCS and spotted this post which seems simalar.

the codes might mean more to you

 

Thanks, yes Aston_Bodger suggested the compressor solenoid valve N280 last night and its definitely on the suspect list.

 

The other suspect I've got my eye on is the smaller fan on the condenser/radiator. I've yet to see it move since my air-con problems started and that doesn't seem right.

 

The workshop manual online says the compressor solenoid valve is regulated by a PWM signal from the Climatronic control unit. I had a look at that data and that seems to vary between 80 and 95 (range is 0 - 200) which corresponds with other posts so I guess that means the signals going out but what's the solenoid valve doing with it or the signal never gets to it, of course. 

None of my fans worked when the A/C was not working, even fired them up with VDCS just to see if it was the fans had packed up, like I said in the end it was the compressor.

 

Shame you don't live closer to MK I would happily get your car on it and show you what's what.

 

 

Trev

Thanks Trev, yes a pity MK isn't just down the road that would be good.

 

Looks more and more like the compressor solenoid valve N280 as you say. 

 

I've realised that I was looking at Evaporator set points rather than actual temps   The figures below were for hot day, warm day, cool day...I'm guessing they say it's not doing anything!?

10 – 0 Evaporator Temperature °C	33.6	18.6	11.6
10 – 1 Liquid refrigerant pressure bar	07.6	04.8	04.0
10 – 2 Liquid refrigerant temperature °C	20.0	20.8	20.0

 

David

I would say that's dead as a dodo.

 

New compressor, how olds the condenser?, only they recommend changing the drier pack too, but the dealers have stopped selling them now so the only way to change the drier is to change the condenser, got mine from Euro car parts and did it myself, handy being a tech, still took 3 hours to rip the front end off and put it all back.

 

 

Trev

20 minutes ago, Aston_Bodger said:

I would say that's dead as a dodo.

 

New compressor, how olds the condenser?, only they recommend changing the drier pack too, but the dealers have stopped selling them now so the only way to change the drier is to change the condenser, got mine from Euro car parts and did it myself, handy being a tech, still took 3 hours to rip the front end off and put it all back.

 

 

Trev

 

Still 1 hour faster than me, took me 4 hours.. 

 

Had some screws which were almost gone due to rust, so it was a pita to get them out. (Had to remove tyres so I could use my dremel to cut a hole so I could fit a better screwdriver)

 

But for beeing an IT guy who sits usually at a desk, I was still happy with the result

 

(At my car the drier was part of the condensor, so I had to replace the whole package, mine was leaking on top of the drier)

 

I've made a short description how to do it, posted it on https://www.skodaforum.nl/forum/i/o2-airco-condensor-vervangen.33273/  (Use google translate). Think a RHD doesn't differ that much on the front from a LHD, think you only have to mirror the images (and description)

 

Sorry, I don't mean to hijack the thread but I've also recently been having some AC trouble. I thought I would give it a quick scan before seeing if a re-gas helps.

Do the following values sound ok?

 

                Address 08: Auto HVAC  (3T0 907 044 AK)

18:40:00
  IDE00019   Voltage terminal 30 13.6 V
  IDE00025   Coolant temperature 63 °C
  IDE00198-ENG100282   Refrigerant pressure-MUX Kaeltemitteldruck 6.4 bar
  IDE00965   Compressor shut-off requirement Compressor active: no shut-off condition is present 
  IDE00966   Compressor current: actual value 0.820 A
  IDE00967   Compressor current: specified value 0.820 A
  IDE00968   Compressor speed 1000 /min
  IDE00969   Compressor load 2.2 Nm
  IDE00970-ENG103807   Coolant fan activation: actual value-MUX Lueftersteuerung 10.0 %
  IDE00971   Coolant fan activation: specified value 0.0 %

  

Aston_Bodger:  Thanks Trev. I can't complain at the age of the bits. I've had my Occy 11 years from new and other than the usual things all I've needed was a new wheel bearing so everything is as old as the car. That's most of the reason I've kept it so long - I've never had a car that's been this reliable before but now its getting arthritic (like me) !

 

DJSmiley:  Thanks for your help. I'm afraid I've no tools anymore and have arthritic issues so I'm not up to doing the work myself. But, as an engineer I naturally want to understand what's going on and challenge the garages if they try to tell me rubbish.

 

Squibble:  I don't have VCDS so I'm only going by the Climatronic on-board diagnostics. However I've got sore eyes with looking at everyone's stats the last few days and yours tie up with many. My symptoms are no cooling and fans don't turn. Halfords (perhaps not the best) said my gas is ok, no leaks, compressor okay and condenser okay. Aston_Bodger suggests that the solenoid regulator valve in the compressor is a regular problem and as I understand it doesn't tend to give much away in diagnostics so no compressor code on the VCDS.

Just for info, I've come across this list of Climatronic onboard diagnostic compressor codes...  (press face-fan and ECON buttons simultaneously then 'tune' left hand temp control to 11 and fan speed control to 6 and read off the value on the right hand temp control LCD to get to register 11- 6 for compressor code).

 

Mine still tells me 0 so I'm overjoyed at there being no problem!

Breakdown of compressor shut-off conditions on Climatronic onboard diagnostics

0 Compressor on (no shut-off condition detected.)
1 Compressor off (pressure in refrigerant circuit was or is too high.)
2 Compressor off (basic setting not performed or not performed without error.)
3 Compressor off (pressure in refrigerant circuit is too low.)
4 Compressor off (engine nor running or has been running for less than 2 sec.)
5 Compressor off (engine speed is below 300/ min.)
6 Compressor off (compressor switched off by ECON118°C.)
12 Compressor off (request from the engine control unit, via data bus.)
13 Compressor off (faulty signal from refrigerant pressure and temperature sender -G395.)
14 Compressor off (fault in data bus system.)
15 Compressor off (the pressure in the refrigerant circuit in this driving period was at least 30 times too high.)
16 Compressor off (the measured temperature downstream of the evaporator has for over a minute been below 0°C.)
17 Compressor off (measured temperature downstream of evaporator below -5°C.)
18 Compressor off (there is no valid measured value for the ambient temperature, possibly both ambient temperature sensors -G17 and fresh air blower intake duct -G89 defective.)
19 Compressor off (-Climatronic control unit -J255 was switched on via the "auxiliary heater" function.)
20 Compressor off (readout currently vacant)
21 Compressor off (measured ambient temperature was below -8°C and is still below
-5°C, there is no request for automatic recirculated air mode or the measured ambient temperature was below +2°C and is still below +5°Cand the "automatic recirculated air mode" function is not active.)
22 Compressor off (measured passenger compartment temperature below +8°C. The measured ambient temperature was below -8°C and is still below -5°C. A request for
recirculated air mode has been received.)
23 Compressor off (via the data bus system a fault message for activation of the radiator fans was sent, e.g. by the relevant engine control unit, and received by the Climatronic control unit -J255.)
24 Compressor off (readout currently not used.)
25 Compressor off (readout currently not used.)

To be honest, I have never tried the on board diagnostic thingy, I just plug my laptop in and read the measured values.

 

I also swapped my single zone system for a dual zone system myself 4 years ago and its still going strong (touches a bit of wood)

 

That's how I know the compressor was goosed.

 

Trev

1 hour ago, Squible said:

Sorry, I don't mean to hijack the thread but I've also recently been having some AC trouble. I thought I would give it a quick scan before seeing if a re-gas helps.

Do the following values sound ok?

 

                Address 08: Auto HVAC  (3T0 907 044 AK)

18:40:00
  IDE00019   Voltage terminal 30 13.6 V
  IDE00025   Coolant temperature 63 °C
  IDE00198-ENG100282   Refrigerant pressure-MUX Kaeltemitteldruck 6.4 bar
  IDE00965   Compressor shut-off requirement Compressor active: no shut-off condition is present 
  IDE00966   Compressor current: actual value 0.820 A
  IDE00967   Compressor current: specified value 0.820 A
  IDE00968   Compressor speed 1000 /min
  IDE00969   Compressor load 2.2 Nm
  IDE00970-ENG103807   Coolant fan activation: actual value-MUX Lueftersteuerung 10.0 %
  IDE00971   Coolant fan activation: specified value 0.0 %

  

Is you A/C working or not?, cos looking at the compressor shut off code It should be working.

 

Trev

30 minutes ago, Aston_Bodger said:

Is you A/C working or not?, cos looking at the compressor shut off code It should be working.

 

Trev

 

No, it's definitely not been working. I've had several really warm car journeys recently :/ 

Edit: Do you not think a re-gas will help then?

Edited 18 May, 20188 yr by Squible

 IDE00965   Compressor shut-off requirement Compressor active: no shut-off condition is present 

 

I think we have the smoking gun there, its no good looking for a voltage it don't work that way I have found out.

 

You should have a compressor shut off condition of some sort, the engine ECU can do it too, when high revs are required, normally this will be 0 if its working. Pressure seems fine to me, its about what I had when mine was not working, that's the first thing I checked.

 

Do you know anyone with VDCS?, that will tell you straight away.

 

Trev