AC on ECON and fault code

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4.2 V8 40v biturbo - 480 bhp (plus)
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skyegtb
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AC on ECON and fault code

Post by skyegtb » Thu Jul 11, 2024 6:16 pm

On my 2003 RS6 the AC has stopped working with the ECON light on solidly. I have owned the car for many years and have had the gas re-filled on average every 3 years due to the same thing happening. In the past I didn't even check for fault codes I just correctly assumed that the gas was low and a top up was required, with the system coming back to life after new gas was added. Anyway, this time the same thing happened but on this occasion I did some scanning and the attached fault code 00819 was stored along with the 'compressor shut off criteria' of 3. Am I correct in assuming that I am just low on gas again, or does the fault code from G65 suggest that the sensor may be at fault? I am unable to minitor system pressure with the AC running as the ECON is on solidly. Presumably 1.0 bar is a very low value when the system is idle?
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2003 RS6 MTM 568

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Shoppinit
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Re: AC on ECON and fault code

Post by Shoppinit » Thu Jul 11, 2024 6:19 pm

The high pressure switch is a common issue and an easy fix. No need to drain the system.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Thu Jul 11, 2024 6:32 pm

Shoppinit wrote:
Thu Jul 11, 2024 6:19 pm
The high pressure switch is a common issue and an easy fix. No need to drain the system.
Yeah, I've done them a couple of times on other Audis. Thats the sensor at the drivers side of the AC condenser isn't it? Pic from when I did the one on my allroad. 8D0959482B is the part number, is that correct?
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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Tue Jul 23, 2024 4:03 pm

OK, I thought that the sensor was bad as it was giving a low pressure fault and reading 1 bar pressure, but in reality the sensor was good and the system was completely out of gas, and a re-charge fixed everything. Now reading 10 to 12 bar when AC is working. No leaks were found in the system , just the fact the car had been in storage for 6 months not in use and presumably the gas had escaped past a dry seal or something.
2003 RS6 MTM 568

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Shoppinit
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Re: AC on ECON and fault code

Post by Shoppinit » Tue Jul 23, 2024 4:23 pm

Huh. That's annoying. Mine sits for months, also, and today I was thinking that it wasn't blowing very cold.

Did you get it done or did you do it yourself? I'm tempted to try a top-up myself.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Tue Jul 23, 2024 4:32 pm

Did it myself with an AC Pro bottle. Took the whole bottle and now works like a dream. Been using these bottles for many years now on various vehicles and find them to be really excellent. If you do use one, make sure to add gas before starting the engine, as that will put enough in to get the AC to actually run, as otherwise it may not activate and will prevent gas from being added. After that it takes around 10 minutes of constantly adding a little more at a time. The good thing with Vagcom is that you can monitor the system pressure when doing the work which makes it very easy. I pressurised it up to 12 bar with the AC on full blast, on recirc mode.
I have probably topped the RS6 up 6 or 7 times in the 16 years I've had it, and the last 4 were with these bottles, but on all the previous fills I didn't use the Vagcom. I only used it this time as I was convinced the G65 had gone bad!
2003 RS6 MTM 568

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Shoppinit
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Re: AC on ECON and fault code

Post by Shoppinit » Tue Jul 23, 2024 5:25 pm

Awesome. I'm going to try that then. I've got an AC manifold / gauge thing to measure pressure and fill, but looks like you don't necessarily need that with those AC pro bottles.

This them?

https://www.amazon.co.uk/Pro-C-Professi ... B0B9LXMZVF
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Tue Jul 23, 2024 7:09 pm

Yes, you need a gun or a tap. I have the non digital version of that gun and it works just fine.
2003 RS6 MTM 568

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Shoppinit
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Re: AC on ECON and fault code

Post by Shoppinit » Tue Jul 23, 2024 7:15 pm

Gotcha. How much gas did it take? There doesn't seem to be much in the bottle. :shock:
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Tue Jul 23, 2024 7:18 pm

2003 RS6 MTM 568

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skyegtb
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Re: AC on ECON and fault code

Post by skyegtb » Tue Jul 23, 2024 7:19 pm

There is 510g in a full bottle. Normally for a top up I have used between a third and half a bottle, but if the system is empty then a full bottle. Also, you can get the gas for £50 at shops, the eBay link was just to show the type I use
2003 RS6 MTM 568

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