A/C Problems-06 Jetta TDI

DunnTDI

Member
Joined
Aug 3, 2017
Location
VA
TDI
06 Jetta TDI PD BRM 1.9L
Struggling to understand what my AC system is doing. On start up and idling. It Blows hot air. I've read a lot of different forums and looked into different possibilities. No leaks, holds high pressures. Took a picture of current low and high side readings. Low side reads around 90 and high side is around 330ish. Those seem way off. Are these typical readings for the MK5 AC condenser systems? When I drive for a while on a highway I have noticed that the air begins to blow somewhat cold air. Not the best but definitely an improvement from the hot normal air. Any thoughts? I read that it might be a front fan went out.
 

relumalutan

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Dec 6, 2012
Location
Michigan
TDI
06 Jetta TDI Special Edition
Very simple to diagnose: turn the AC on, open the hood and check to see if both fans are turning. If they don't, they might be toast. There is another condition that can prevent the fans from turning: a bad RCV valve (it goes inside the AC compressor, you can see it with the hood open, it has a black cable going to it). If the RCV valve doesn't engage when you turn the AC on, the fans will not turn.In that case you will discharge the system, replace the RCV valve and charge it back. When the RCV valve is bad, often it will engage, but with a long delay. The easiest way to diagnose the problem is to check the fans is with VCDS.
 
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keith102

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Mar 10, 2005
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Ball Ground, GA
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2015 Golf TDI 6spd
I had a similar problem with my 06 TDI where the AC would not blow cold at low speed or in traffic but once at Cruising speed it improved. Pressures were fine. Replaced the RCV valve and recharged and it's back to normal. Got the replacement rcv valve from polarbearinc.com.
 

Diesel126

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Aug 1, 2009
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North West Nj
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2013 Passat SEL TDI DSG / 2006 Jetta TDI DSG / 2011 Touareg TDI Executive
I am currently have a similar issue. My A/C blows cold on the highway but in traffic A/C starts blowing warm air. I just found out today that my cooling fans are not working during A/C operation. I checked all the fuses and electrical connection and all seams fine. Not sure if a bad RVC valve would cause the fans not to turn on during A/C use?
 

relumalutan

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Dec 6, 2012
Location
Michigan
TDI
06 Jetta TDI Special Edition
I am currently have a similar issue. My A/C blows cold on the highway but in traffic A/C starts blowing warm air. I just found out today that my cooling fans are not working during A/C operation. I checked all the fuses and electrical connection and all seams fine. Not sure if a bad RVC valve would cause the fans not to turn on during A/C use?
A bad RCV will prevent the fans from turning in. "Bad" does not necessarily mean the RCV valve will stop to work completely, often it still works, but with a huge, annoying delay. In your case, it seems the fans are not working, since the RCV valve apparently engages (you have cold air at highway speed because the air rush from outside the car does the cooling, instead of the fans). Before you start throwing money at parts, better find someone with VCDS and do a fan test. Or even better, look on the sale section of this forum or on vwvortex and buy yourself a VCDS microcan, you will never regret investing money in it:
http://forums.vwvortex.com/showthread.php?8762681-FS-Ross-Tech-VCDS-Micro-CAN
 
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Diesel126

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2013 Passat SEL TDI DSG / 2006 Jetta TDI DSG / 2011 Touareg TDI Executive
A bad RCV will prevent the fans from turning in. "Bad" does not necessarily mean the RCV valve will stop to work completely, often it still works, but with a huge, annoying delay. In your case, it seems the fans are not working, since the RCV valve apparently engages (you have cold air at highway speed because the air rush from outside the car does the cooling, instead of the fans). Before you start throwing money at parts, better find someone with VCDS and do a fan test. Or even better, look on the sale section of this forum or on vwvortex and buy yourself a VCDS microcan, you will never regret investing money in it:
http://forums.vwvortex.com/showthread.php?8762681-FS-Ross-Tech-VCDS-Micro-CAN
I tested my cooling fans with my VCDS yesterday and they do not turn on.
I will pull the fan shroud and test the fans manually toady.
 

gassprint1

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Aug 14, 2017
Location
Knox iN
TDI
2006 jetta
I tested my cooling fans with my VCDS yesterday and they do not turn on.
I will pull the fan shroud and test the fans manually toady.
after you do the manual test and they don't works, it might be your option to pop the back cover off and check for stuck brushes. i have seen many different places about it and even videos. if they do work manually, then the module is probably bad. my ac stopped working lil over a week ago. test power wires at fan, ac solenoid an such with all having power. so it's narrowed down to the ac solenoid or maybe the fan module...hell...both. i don't have the VCDS to test with and don't know anyone around here that does. i'm probably guna order the solenoid from the place in florida and i may even just buy the fan module an try it for $25. checked everywhere and see no info of people trying the module out.
 

Diesel126

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2013 Passat SEL TDI DSG / 2006 Jetta TDI DSG / 2011 Touareg TDI Executive
I removed the fans and tested. The small passenger side fan did not work at all. and the drivers fan did not work at first but I gave it little spin by hand and it started to spin by itself. I ordered a new shroud and fan unit. Installed it tonight and all is good now. A/C is ice cold while idling and sitting in traffic again.
 

gassprint1

Active member
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Aug 14, 2017
Location
Knox iN
TDI
2006 jetta
I removed the fans and tested. The small passenger side fan did not work at all. and the drivers fan did not work at first but I gave it little spin by hand and it started to spin by itself. I ordered a new shroud and fan unit. Installed it tonight and all is good now. A/C is ice cold while idling and sitting in traffic again.
was that on your 06'?
if it was, i'd be interested in trying out the fan module. sounds like the brushes in the fans were the problem.
 

Diesel126

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2013 Passat SEL TDI DSG / 2006 Jetta TDI DSG / 2011 Touareg TDI Executive
was that on your 06'?
if it was, i'd be interested in trying out the fan module. sounds like the brushes in the fans were the problem.
Yes, 06 BRM
I paid $155 for the whole new unit.
currently at 330,000 miles
 

SuperZ28

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Jul 28, 2017
Location
Maryland
TDI
06 Jetta TDI
I'm also having some A/C issues with my 06 Jetta. I've exhausted almost every route I can think of. I replaced a bad RCV, the G36 hi/low pressure sensor, both fans are brand new, recharged system which holds pressure and no leaks and I also put a tested and working climatic control unit in... still no A/C. I have VCDS and once I test the the system the fans both kick on and everything checks out okay. But again still no A/C. I'm kinda stumped.
 

gassprint1

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Aug 14, 2017
Location
Knox iN
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2006 jetta
well ****... there supposed to be a test that can be done with the vdcs that check all the sensors and stuff.
 

DunnTDI

Member
Joined
Aug 3, 2017
Location
VA
TDI
06 Jetta TDI PD BRM 1.9L
Referring back to the RCV, I noticed on PolarBearInc there are several different types of RCV specified for several of the VW compressors. How do you know which one? Do i need to pull my RCV and then order the closest similar design. Or is there a specific I just need to look for?
 

DunnTDI

Member
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Aug 3, 2017
Location
VA
TDI
06 Jetta TDI PD BRM 1.9L
Installed new RCV. No luck. AC still blows hot. Fans do not run. Will begin to check Fan assembly. Do not have VCDS, any good ways to test fans? simply run 12v to fan assembly pig tail?
 

gassprint1

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Aug 14, 2017
Location
Knox iN
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2006 jetta
no, that wont work. there is always power at the fans, red wire, and the computer sends signal to the control module to turn them on. if you got the valve changed, system all charged up with 18-19 oz of freon.....take it down the road at 55 or so mph. if the system is working without fans, it will cool from the air flow. if not, then it's probably the compressor. i wasted 75 on a new valve and all that goes with it an didn't works. got vcds next week and watched the metering blocks an such...compressor was the problem.
 

gassprint1

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Aug 14, 2017
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Knox iN
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2006 jetta
look on ebay for the compressor. there is a place from california that sells them at a good price for around 180 with everything needed to replace. compressor, dryer, orings, pag46 oil.
 

Rx7145

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May 21, 2017
Location
Ohio
TDI
2006 Jetta BRM
Could it be the pressure switch? It can be changed without draining the system.
 

gassprint1

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Location
Knox iN
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2006 jetta
i wondered if mine was bad at the time i had issues lil over a week ago till i scanned with vcds. i kinda doubt it is. i highly say for you to spend the 200 at ross tech or idparts and get the cable. i was glad others pushed me to get it and happy i did. it does and shows some amazing stuff. when you have an issue in the future, you'll be glad you got it. how i determined my pump was bad, was i used vcds and opened the screen that showed ac pressures an such. every time i pressed the ac button, nothing changed in pressures as it should. vcds will allow you to kick on the cooling fans to see if they work and other stuff. you can do some of those neat things you see in videos also...such as when you hold the fob unlock button, it can make the windows roll down or up. won't open the sun roof, but will close it. get an air bag light or have to change something, you can do it yourself and won't have to take it to the dealer. everything in our cars has it's own control module. you can check everything individually...with the money you spend on thing and ur ac still doesn't work, you could have already paid for it. like i said, i wasted 75 on the valve when that was virtually half what the vcds costs. don't short change urself and but a knock off cable system.
 

DunnTDI

Member
Joined
Aug 3, 2017
Location
VA
TDI
06 Jetta TDI PD BRM 1.9L
Okay i will have to look into getting a VCDS kit. I did test my AC system. When I turn on the AC system going 55 mph and up. It does begin to blow cold air. Much better than it ever did in the past. Again, im not sure how cold it should be kicking out, as i have had other cars which blow ice. This car does not seem to blow ICE. but much better than before. So can i just read voltage in at the pigtail. and See if im picking up the signal when I toggle the AC switch? which would indicate if my fan assemblies are fried. Would that work?
 

gassprint1

Active member
Joined
Aug 14, 2017
Location
Knox iN
TDI
2006 jetta
there should always be voltage to the fan control module. i don't know what the computer signal is to tell the fans to kick on. i research it and found nothing. i kinda doubt you had ac air coming from the vent but rather cool outside air instead. before going thru alot of extra work, i'd spend the 200 an get vcds before doing anything else. you'd probably have it in a day being ross tech is in PA
 
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