Auto Sparky Conduct question.

05 Audi A3 gets taken to an auto sparky/air con specialist, the car has had weak cooling ability for some time and has once had the eco light stick on (which means an error with the system).

The technician checks the refrigerant pressure (so far so good) but finds that to be O.K.At this point, without scanning for any error codes decides to replace the refrigerant control valve based on the fact that the compressor still appears to be working.

Problem is not fixed, customer is advised it must be the internals of the pump causing the problem and the pump needs replacing. A/C valve caps are left sitting in the passenger footwell and customer is issued with a $500 bill.

I have a quick look at the car at this point. Scanner shows evaporator temp sensor to be sitting constantly on 0 degrees and an associated error code. Also a code for the recirc flap motor and interior temp sensor.

When the owner goes back to the Auto Sparky/AC tech to pick up the bill, after the customer mentions what I found the Auto sparkytakes the car around the corner to a "mate" who finally scans the vehicle. Auto sparky looks at error codes and decides its a job for an Audi Specialist.

Now here is my take on it, I am NOT an A/C specialist and I want to hear your thoughts on the technical issues AND the technician's conduct. Please just accept my version "as is" for these purposes, its all we have to work with and I don't want to hear about two sides to every story or trolls self pleasuring over an Audi with a fault.(sorry to be blunt).That said, I am sympathetic to busy technicians and do want to hear if I am being too harsh in my opinion, or good sound reasoning that may have caused the technician to do as they did.

My take on the technical side is that with the evap sensor showing 0 degrees the system probably throttled or stopped the refrigerant circuit thinking the evaporator was freezing up, thus causing the lack of cooling. Looking at flap valve and interior sensor data, the interior sensor had a code but appears to still be working fairly accurately. Both should be replaced in my opinion but are unlikely to be the problem.

I think the technician should have scanned the car either immediately or straight after checking the refrigerant.

I think its very unprofessional that an auto sparky doesn't have the equipment to scan such a car and appears to take educated guess's as a substitute for the right gear. I am also dissapointed that the caps were left off the A/C valves.

I don't think the customer should pay the whole bill, but would be interested on your thoughts.

The vehicle will be over my way in a couple of months and I intend on replacing the evap sensor, flap motor and interior temp sensor. I think these items should be replaced before anything else is done or further money is spent. I also think it fairly likely that the evap sensor will solve the problem.

Sorry this is a long spiel, I wanted to give the whole story as much as I am able. Keen for your thoughts.

IMHO only thing custy should pay for is a diagonistic fee.Tech has replaced a part on a guess and it didnt work.Old part should be refitted and system restored to state prior to the tech "fiddling".My guess diagonistic fee should be about 30mins labour.

Evap sensor is likely only a variable resistance.On that basis can prob be bypassed with a suitable resistance (light bulb maybe) which would get the system operating for further testing of flap motors etc.

Thanks for that, very much my take on it too. Although I am a bit reluctant to have the technician fiddle with the car any further, especiallyif they get the pip with the situation.But you are right and I agree.

That's a good idea regarding the valve and would have made more sense to have done that rather than replace it. To be completely fair, I don't know for certain that the technician did not do this first, but I would have expected to possibly see some evidence when I scanned it if the valve had been causing the problem. The general feel of the situation also makes me suspect this was not done first.

Thanks for a great response.

Oh, and with regard to my testing, I did actuate the flap motors etc, my VCDS allows me to have a really good look at things, my only enemy was time available.

ps not a singy import is it.I've struck a few singy's where the air flaps have been sealed in the full recycle position for some odd reason.In one case the flap motor rods had been physically broken off and the flaps screwed shut.What was even sillier was it was a dash out job to get to the bits.Removed screws, fabricated some new rods and all worked as designer intended.Why would someone go to all that bother to disable something!

Crazy aye!
This one is a Jap import, everything appears to be there. This is very early 05, the flap motors for the first 18 months or so were not a great design on these and VW changed them just after this car was built.

It seems that the few little VW updates that are usually done by dealers at service were not done on this car in Japan. No big deal as its easy and fairly inexpensive stuff and the car was about 8K cheaper than others for sale at the time.

Incidentally, with those flap motors aside from the Japanese not seeming to check and replace them for free like most dealers (possibly customer does not take them for servicing), I suspect that city cars over there likely give the flap motors a real workout.
My theory is the air quality sensor would activate the recirc flap quite often in such conditions.

thejazzpianoma wrote:

. the flap motors for the first 18 months or so were not a great design on these.

Careful Jazz the trolls will hang you for admitting that VW made a mistake.

Was the return (suction ) lineto compcold&thesmaller liquid line warmwhenrunningatsay 2-3000rpm !If so then wasntthe TX valve, &pressure gauges wouldhave told himif it was a mechanical problem .Id say its a control problemasflap actuator isnot working . perhapsnot allowing theair through the evaporator .

The recirc flap would let air through the evaporator in both open and closed positions would it not! Otherwise the A/C would not work on both fresh and recirc. or am I missing something.
Either way the flap motor does still seem to work most of the time, but I will be replacing it as a matter of course.
Sorry I don't know what the line temperatures were doing when they took it to the auto sparky.

I have been meaning to re-check and lookup the value on the flow valve, I seem to recall it showed a value which looked to me like it would likely be fully closed, which made sense for my evaporator temp sensor theory. It wasn't cooling at all by the time I looked at it.

Here you go, I took 0% to mean 0% open (as in the valve is fully closed), does that make sense! Remember A/C is not something I normally play with so I could be missing something obvious.

Address 08: Auto HVAC(8P0 820 043 H)

09:06:46
0.000 AA/C Regulating Valve (N280)
0.0 %A/C Regulating Valve (N280)
21.5 %High Pressure Sensor (G65)
6.0 barRefrigerant Pressure
6.0Current Shut-Off Condition
0.0Last Shut-Off Condition
0.0Last but One Shut-Off Condition
0.0Last but Two Shut-Off Condition
750 /minEngine Speed
0 0 0Consumer Shut-Off
0A/C Compressor Regul.Valve (N280)

Not a tradey, but this is how one customer would feel about the situation. Why should I pay $500 bucks to a) not have the problem fixed, and b) replace a part that is not demonstrably faulty. Labour cost quite a lot, but that is ok if the labour is skilled. The whole reason for paying someone qualified extra is because they shouldn't have to stumble around taking a stab in the dark.

job NOT done part replaced with no need. why would there be a bill for not fixing the problem!
Sorry Jazz this aint a dig at you but With VW/Audi AC work you MUST go to people with the equipment and EXPERIENCE to work on that product or you end up with exactly the situation you are outlining here.
When working for a dealership dealing in euro stuff we ALWAYS sent the cars to a VW specialist if there were AC issues.
It always ended up being cheaper in the long run