Hi, I have an issue on my fabia (2009 Greenline 1.4 diesel), with the air con system. It seems to blow cold sometimes, but when run slowly, it stops chilling.

Had a recent re-gas but that did not cure the issue. I tried the Climatronic a/c Diagnostic check, via the buttons on the panel and came up with the code 318. that is on the left of the display, where on the right I have 02, in the larger display. I think this suggests two faults but am unsure and with my research so far, the 318 code would appear to be related to the a/c high pressure switch. I have seem some on Ebay (Dealer ones are quite pricey) But I am unsure as to the exact type and location.

 

Some have Schrader type valves that just screw on, sealing themselves, like tyre valves, then the wiring plugs on the top. Again, i am unsure as to if mine has this without seeing it on the car!

 

Does anyone KNOW where the switch is and what type I would have? Thanks in advance.

Is that the G65 sensor you are on about ? If so it's on the left as you stand in front of the car looking at the engine. About half way between coolant reservoir and headlight.

It does just screw on to a schrader valve. I replaced one unnecessarily. What does your sensor read in vcds measuring blocks. It should read as per outside temp in this table. This was mine and it was fine.

Hi, I have no access to VCDS so don't know... I found the fault code on the a/c panel on the dash, where you press recirc and econ buttons to get the codes listed... 

I found the meaning of the fault code listed and I think that too, mentioned G65 sensor. Did you buy sensor from dealer? They are a bit pricey. Seen some on eBay, etc for around £15-£20 and even some Chinese sellers selling them for as little as £9 but not sure I'd trust them!

Your location says east London. I'm in Newbury Park, Ilford.  You want to pop by and I'll plug my VCDS cable on and we can see what yours reads. It may give you better fault codes too. You can also try my old G65 sensor (it was working fine) if you really wanted to, depending on your VCDS reading result.

I changed my G65 as the sensor read zero, but it was zero because it needed a regas.

Edited 30 July, 20187 yr by aubrey

That might be handy if you have time to spare... I was actually looking at one of those carisoft readers for VAG cars, which could be handy. I have a little handheld OBD11 reader that says no codes found but the a/c system is different from the other stuff usually detectable. I originally got that for my daughters Toyota but it is handy. When are you most likely to be free? Perhaps you could message me.

 

I took a little look at the car just now and I think I spotted it from your description. I thought it would be larger then that but it is quite slim. Just behind my fuel filter canister, with a black spiral bound cable attached to it.

 

I live in Bethnal Green, by the way. I take students all around Wanstead, Barking, Goodmayes etc for driving tests.

Edited 30 July, 20187 yr by mrgf

With the help from Aubrey, I got the codes checked out. It seems a fault but not with the sensor. He swapped over to another one he had after clearing the fault codes and the a/c seemingly working but today, it did the same thing, blowing cold, then warmer after a while. Also, still getting the code 318 coming up now. 

 

Would anyone know if a duff, weak battery would affect the output of the a/c system as this seems the only other issue I can think of. I tested the battery and alternator on one of those little testers that have LED lights, showing the level and although it seems to go flat easily, it seems to charge (I suspect it to be weak so the charge is gonna be a very low capacity) And the tester shows the alternator to be charging without overcharging. I will try out a different one of these testers too as I purchased a replacement some time ago and it has never came out of its packaging, whereas the other one is in the region of 20 years old. I wonder if it is still up to the task!

 

The actual battery is a Bosch one, with a 5 year warranty, that has been on the car for around 4 years so might just be dying. (Must find that receipt)!

I doubt this is battery related. Have you checked that the radiator fan is working correctly (both of them if there are two)?

Do you get colder air out of the A/C if you are travelling faster?

The smart money for anyone willing to give a bit of help would have been to watch what the system was doing while it was initially running okay and what is was doing when it started to stop cooling. Watching  refrigerant pressure and evaporator temperature might just have pointed you in the right direction?

I have only the one fan that I am aware of and I guess it would be obvious if there were two. That one was replaced a few years ago as it packed up. I deffo know it comes on at least some times as I have seen it and also put a felt pen mark on the fan and the surround, to see if it moves and it does. I do seem to get cooler air if driven faster and it seems to be more likely to be warmer if driving slowly or stationary for some time. I switched the battery for a smaller spare I had, charged the normal one and re-fitted it. It went flat again over a few days so is just on charge again, with spare back on the car. As mentioned, the tester says it is charged to a certain degree once charged but it just loses it too quickly. It also says alternator output is good and not overcharging, which I know will kill a battery in no time, if it was ! 

 

The problem with testing the cooling system is knowing when it will and won't operate. Aubrey found and cleared the codes and all looked well but it reverted the following day, to what it had been doing so it seems to still be happening. Pressure at the sensor when not running was 6bar.

I can help you to check out the fan operation if you want. First thing to look at is the fuses on top of the battery. Strip fuse 6 (50 Amp) does the high speed fan operation on your car I think - assuming it was built after May 2008 -, and blade fuse 8 (30 Amp) does low speed.

If both are intact, you can try triggering each speed via the radiator thermoswitch connector to see whether they both work. With ignition switched on, link pin 1(brown wire) of the thermoswitch loom connector to pin 2  (brown/blue wire)  for low speed operation, and to pin 3 (brown/green wire) for high speed.

Edited 2 August, 20187 yr by Wino

Thanks, Wino. I will read that a few times to make sure I understood properly, then give it a try. It was indeed built after that date. It is a late 09 model on a 59 plate. 

Not checked the fan yet but sorted the battery. Had trouble locating my receipt for it but on live chat with Carparts4less spokesperson, she looked up my profile, found the original order number, gave me that, along with an authorisation code and said I should go to my nearest Eurocarparts branch and they will exchange it. (Yes, you read correct). So I did this and they did indeed change it. At first the guy asked about the invoice but I told him what happened, showed him the codes etc and without even testing the old battery, he swapped it for a brand new one. One issue solved... 

 

Oh, BTW, Don't take it for granted that a new, fully charged battery IS fully charged... I tested mine both on the little LED tester (50-75% charge) Then on my actual charger. This stated 60% charge so I slapped the battery on charge to top it up properly. I don't want to start the day with a 60% charged battery, which will not really get charged much more over time. Makes you wonder why they go weak so early. It used to be common practice to charge prior to fitting but these days, with sealed units, they are usually described as "Ready to use"! Its 100% now. 

Edited 2 August, 20187 yr by mrgf

Probably the wrong time of year for getting a "fresh" battery - ie in a good state of charge, sales of batteries should be low at this time of year hopefully!

Whilst I had the battery off, I removed the plastic under tray and checked the power steering fluid level. It was right at the bottom of the dipstick, although minimum is only just above that, by a mm or 2. I think I will either top it up with a small amount or, depending on how much I need to buy and how much the system holds, syphon out the older fluid and re-fill with new. Its a piddly way of having to check the fluid, though. Remove battery and under tray, just to access the filler cap. I would strongly advise anyone who is thinking of shortcutting this method, not to as when I got to the filler cap, it was coated in grime, that could be bad if it inadvertently managed to enter the reservoir! Clean off the cap well, prior to unscrewing and be careful not to allow dirt to ingress the system!

I have always gone by the condition of the base of the cap, ie wet means okay, once I added some in using a clean syringe, then needed to remove about 90% !

Its just touching the bottom but only just.

That said, the difference might only be 100ml or so!

More like 10ml.