Need some advice on Air conditioning diagnosis - Not blowing cold

PlasticMac said:
There is no clutch on the A2 AC compressor, it runs all the time, with flow controlled by the N280. If you turn the AC off, (Econ), the N280 reduces flow to around 5%, but never zero.
Have a read of this, page 59 on. You'll understand it a lot better then.
Mac.
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Sorry, I meant the plastic 'emergency breakout' bit that joins the pully to the compressor drive shaft. This has not failed and the compressor shaft and pully rotate as one. I believe the compressor is OK (and certainly not seized.
 
Hi Mac,

Page 63 describes what I read on the denso website. Basically you could still have a seized compressor and the pulley rotating freely.

EDIT: @Oskar beat me to it.

Evros
 
If the compressor was doing anything, I think you'd see a pressure in Group 001, Block 04, regardless of the N280.
What do you see there?
Mac.
 
As I need to de-gas to fix the issue (from what I can determine), I have ordered the new N280 and will install into a known working comp I already have and swap the whole unit, and regas. Let’s hope that sorts it.
 
Oskar said:
Between 3.6 and 5.2 bar in box 4. Never below 3.6 though.
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That looks OK, the expected range is 2.6 - 29 Bar, (from the label file).
That looks close to the minimum, so could be that the AC thinks it's off, or, as you suspect, The N280 is stuck at the minimum.
Watching with interest, good luck.
Mac.
 
An unexpected but simple resolution.

Firstly, thanks for all the comments and help. It is really appreciated, and sorry for not providing a small but subsequently important aspect.

I was reading the 'Self Study Technology' document kindly provided by @PlasticMac and I noted the presence of the G191 Center Vent Temp sensor. I went looking for this, but still have not found it. However, this made me think it is perhaps part of the hazard light switch in the center vent. Perhaps it is, or perhaps the switch provides power or a connection of some sort. I had my hazard switch disconnected (intended to be re-located) as my iPad mini solution has taken its place.

I reconnected the switch, tucked it away behind the ipad, and all is well with the air con!!!!

I really did not think the hazard light switch would have made any difference, but it seems to.
VCDS as not thrown up any errors for the missing G191 (and research tells me it will, if the sensor has failed), so I am a little confused really, however maybe it has not failed, but for some reason, without the switch or message from the G191, it won't turn on the a/c.

Of course, I tested this the day after booking the air con guy, but that's the way it goes......

I'll post regarding the ipad install at a later date. This has been (and still is) an on-going install, however it will do what I need, in the manner I need it, albeit looking a little untidy.

I was sure it was blowing cold this morning, and perhaps it was, but now it is back to where it was. Perhaps a stuck N280 released once this morning, but it stuck again.
Air con guy is still coming next weekend, so a compressor swap may do it (for either comp or N280). It's on the bench ready to be fitted.

Now I just need some hot weather!

Thanks again,

Matt
 
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@Oskar your ipad install is similar to the Garmin satnav install I did...

1714229951566.jpeg
 
...and an update on my A/C issue.

The A/C guy thinks it is a pinhole in the condensor, and with the UV light he has, it looks like this is the case. Less than 50% of the gas remained in the system, but enough gas and pressure to not throw any errors, and for the A/C to be slightly cold early in the morning, but not at all cold later in the day.

It all looks and sounds logical, so off with the bumper and a new Condensor and G65 to be installed.

If any member has a new condensor available, let me know, otherwise I will wait the usual 7-10 days from Autodoc.

Let's hope that is the issue..........
 
Hi apologies for the thread hijack but I’ve a fairly simple question (for anyone in the know) on this general topic. My climate control hasn’t been blowing chilled air from the time I bought the car - I wasn’t too sure at the time I bought it in early spring but can definitely testify that in the last few warm days it’s uncomfortably warm. The fan is blowing much harder in the heat when it’s on auto so suspect it’s doing the kind of things it should do though, besides making the interior cool. I don’t know when it was last gassed so hopefully it might just be a case of getting it regassed, but before I potentially waste money doing that are there particular modules I should be scanning for faults? There’s an aircon one isn’t there which would seem to be obvious but are there any others I should look at? And would the FSi-specific label file that I was pointed at a few weeks ago be suitable for this?
If there are no faults then would a regas be the next natural thing to do?

Edit… I take it the label file @Andrew attached further up the thread isn’t the same as the FSi- specific one? In which case do I just swap between the 2 files depending on what I’m scanning for?
 
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Scan the HVAC Controller.
The label file is different to the FSI file. But, again, like the FSI, there is no label file in Lite for the version of the HVAC thats fitted to the A2, (all of them I believe). The correct label file is included in the full version of VCDS, but only in German, but translates OK.
The scan will probably tell you what's up, or maybe, like me and Teresa, you may find a comms error to the HVAC Controller. I cleared mine, and Teresa's, with OBD Eleven. VCDS may work, once the label file is installed, but I'm not sure whether the label file is used for scanning.
Install the @Andrew file in the label folder, same as the FSI one, then scan the HVAC, and, 🤞Clear Faults.
Mac.
Edit, When you do a scan of a controller, the label file name is included on the scan, so the label file plays some part in the scan.
If a label file that matches the controller is not found, VCDS attempts to find a close match, but often, as with the FSI the "close match" isn't close at all. I'm guessing that if it can't find a label it thinks is close, then it doesn't scan, so, maybe once the correct label file, for our HVAC is present, all will be well. Here's hoping Mal.
Mac.
 
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PlasticMac said:
Scan the HVAC Controller.
The label file is different to the FSI file. But, again, like the FSI, there is no label file in Lite for the version of the HVAC thats fitted to the A2, (all of them I believe). The correct label file is included in the full version of VCDS, but only in German, but translates OK.
The scan will probably tell you what's up, or maybe, like me and Teresa, you may find a comms error to the HVAC Controller. I cleared mine, and Teresa's, with OBD Eleven. VCDS may work, once the label file is installed, but I'm not sure whether the label file is used for scanning.
Install the @Andrew file in the label folder, same as the FSI one, then scan the HVAC, and, 🤞Clear Faults.
Mac.
Click to expand...

Thanks I’ll give that a go. If it’s still not working after that then I assume the next step would be a regas?
 
Malcyb said:
Thanks I’ll give that a go. If it’s still not working after that then I assume the next step would be a regas?
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If there are no codes, after clearing, running, then re-scanning, yes.
First scan will be historical, so not useful.
In @Teresa 's case, once the "no comms" was cleared, it started to get cold, when it previously hadn't. Not very cold though, regas I guess.
Mac.
 
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PlasticMac said:
If there are no codes, after clearing, running, then re-scanning, yes.
First scan will be historical, so not useful.
In @Teresa 's case, once the "no comms" was cleared, it started to get cold, when it previously hadn't. Not very cold though, regas I guess.
Mac.
Click to expand...

Ok I’ve just done this but so as not to corrupt the original thread I’ll start a new one…
 
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