GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

Crap A/C issue

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
So, for the past few years my A/C has not worked, and I have just dealt with it as I figured a compressor was a lot of time and $$. Due to a renewed interest in getting the ol' girl back up to snuff, I started digging around and checking things.

Symptoms: No a/c, no small fan running. Engine idles up when a/c is on, but no results.

Checked the freon levels and found them to be satisfactory. Checked the fuses and see no issue there. That got me to wanting to check the solenoid, but due to the angle of the plug, it is a pita to get to test it. I was doing some searching and found that the a/c pressure switch could be at fault. This component being bad would explain why neither the fan, nor the compressor work. As opposed to both of those parts being bad. So after the long winded explanation, does anyone know if removing this part while the a/c system is still pressurized will cause a total pressurization loss, or does it need to be vacuumed first before it is removed? It looks as if it simply screws off of a schrader valve, but I would rather be sure than release a crap ton of freon into the air on accident. Thanks!
 

GTI's

Drag Race Newbie
Location
MD
......... It looks as if it simply screws off of a schrader valve, but I would rather be sure than release a crap ton of freon into the air on accident. Thanks!

It just screws off a Schrader valve, system does not need to be evacuated.

Vcds scan of the system would give you more info on status of system and the compressor shutoff code etc.

"Here is a list of typical Compressor Shut off codes:
- 0 = Compressor ON
- 1 = Compressor OFF: Refrigerant Pressure too high (> 32 bar)
- 2 = compressor OFF: Basic setting not performed
- 3 = Compressor OFF: Refrigerant Pressure too low (< 2.0 bar)
- 5 = Compressor OFF: Engine Start Detection
- 6 = Compressor OFF: ECON Mode active
- 7 = Compressor OFF: A/C System / FAN OFF
- 8 = Compressor OFF: Outside Temperature too low (< 3.0 °C)
- 10 = Compressor OFF: Vehicle System Voltage too low (< 10.1 V)
- 11 = Compressor OFF: Engine Temperature too high (> 118 °C)
- 12 = Compressor OFF: Shut-Off requested by Engine Control
- 13 = Compressor OFF: Vehicle System Voltage too high (> 17 V)
- 14 = Compressor OFF: Evaporator Temperature too low
- 16 = Compressor OFF: Compressor Activation faulty
- 17 = Compressor OFF: No or implausible Signal Pressure Sensor
- 18 = Compressor OFF: Vehicle Speed Shut-Off
- 19 = Compressor OFF: Shut-Off requested by Central Electronics Control (Load Management)"
 

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
My lord man, you are spot on everywhere! Now if only I had a cable to check that! I do plan on ordering one, but where/how would I find that information? Is that a specific block? And seriously, you should have a patreon link to donate beer $$!
 

GTI's

Drag Race Newbie
Location
MD
Module 08 -> measuring block 08-> group 001-> field 1

If you have a climatronic system you can access diagnostic info from it, does a search for how it works and what info is available.
 
Last edited:

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
I do have that, and I browsed a bit. Does not look like too much information. I should probably just bite the bullet and buy a cable already, lol.
 

vwengineer

Ready to race!
Location
Switzerland
It's easy to get all informations on the AC from the menu of the climatronic, look for "climatronic hidden menu" on Google. Gets the same info as VCDS, you also can get refrigerant pressure, compressor duty cycle (actual/requested). Very useful.

That said VCDS is very useful too so it's not a bad idea to get it in fine.
 

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
wuuuuuuuuuut. But it does not look like it does the shut-off codes that I would be looking for?
 

golfballer78

Ready to race!
Location
southbay CA.
Car(s)
08' R32 dsg
wuuuuuuuuuut. But it does not look like it does the shut-off codes that I would be looking for?

What codes? It won’t be anything staring at you like a bright orange light when u drive, who cares. If you worry about every code thrown/stored, even if doesn’t effect drivability, welcome to Vw
 

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
What codes? It won’t be anything staring at you like a bright orange light when u drive, who cares. If you worry about every code thrown/stored, even if doesn’t effect drivability, welcome to Vw

Yeah, was mainly meaning codes that are causing the AC to not turn on.
 

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
Alright! Tested it out this morning after an oil change, and found absolutely nothing. I checked the 11-6 as mentioned, and it was showing 00. Which would me no issue according to the chart. So would that mean that the pressure switch is more than likely good, and I should lean more towards a weak/dead compressor?
 

vwengineer

Ready to race!
Location
Switzerland
There is no pressure switch, only an HP sensor and you can read it using the hidden menu. Note that the compressor is always ON on that model, even if the refrigerant is completely empty.

Have a look at the duty cycle actual vs requested, I think it's around 13-1 to 13-3, if the duty cycle is high and the compressor reaches it, then you don't have enough refrigerant (you can have a look at evaporator temperature to confirm). If the duty cycle is not reached, the solenoid is toast.
 
Last edited:

easy87

l1kez b00st
Location
Texas
Car(s)
GTi
So, went out and tested it out on my lunch break. Temperature out is 60f and it is 60% humidity. Below are the results:

9-0 = 2
9-1 = -28.3
9-2 = 0
9-3 = 1

10-0 = 29.6
10-1 = 5.6
10-2 = 20

11-0 = 82.0
11-1 = 82
11-2 = 82
11-3 = 81
11-4 = 9.8
11-5 = 46.5
11-6 = 0

12-0 = 6.6
12-1 = -3
12-2 = 0
12-3 = 0
12-4 = 0

13-0 = 0
13-1 = 1
13-2 = 2
13-3 = 23
13-4 = 2

19-4 = 10
 
Top