We have a Audi A6 2002 1.9 TDI 130.
When we got the car the ECON light was permantly on. I ran vcds and found a fault with the G65 sensor. Actually it'd been fully removed and the connection damaged. So I repaired the connection, fitted a brand new G65 sensor and had the system recharged.
It then turned out that the clutch ( I say clutch but it doesn't have one as it has a N280 valve) was missing. So I got a new plate for it so it actually did drive the compressor.
With VCDS I see a pressure increase with ECON being turned off and when I turn it on the pressure decreases. But I do not think the pressure goes up enough when the aircon is activated. My A4 goes to 9-12 bar when using aircon. Where the A6 barely hits 5 or 6.
I have run the car for 3 minutes with aircon on, both sides on LO.
A/C Valve (N280) Current: 0.650amp
A/C Valve (N280) Duty Cycle: 64.5%
High Pressure Signal (G65): 19%
Refridgerant Circuit Pressure (G65): 4.6Bar
It seems low, but the actual pressure is fine.
Could this be the N280 valve not opening enough to let the pressure build?