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Discussion Starter · #1 ·
She just turned over 200k miles and still a pleasure to drive. I tried to diagnose the issue where the heater is stuck on and got codes, but beyond my ability to fix. I live in Bradford county PA, and don't know where to go to get it fixed. Live 15 miles south of Towanda and have no dealerships near me, nor any german repair gurus. If you know of a place, please let me know. Thanks
 

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Discussion Starter · #3 ·
I thank you for your recommendation. Seemed a bit too far, so called around to various dealerships and told them the issue and what fault I retrieved- 4FA, recirculation flap. Took it to a dealership with a service advisor that sounded like he knew what I was talking about. Left it for a week and was told that the A/C pressures were somewhat low (over 200k miles, big surprise) and that for $2400. they would replace the A/c compressor. So, I guess I wasted a day of my life driving back and forth twice and a diag fee of $53. Problem is, fresh air and heated air come thru constantly and no A/C even though the compressor is operating. Are all the servo motors the same in this system? Figured I couldn't screw it up any worse that it is. Any suggestions on where to get the servo motor. Seems new is almost $200. and can't afford that much on a guess on my end. Sorry for the wall of text.
 

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I'd try resetting the Climatronic codes, then running the self test again.

A problem with the recirc flap shouldn't prevent you from getting cooling. Conveniently, the recirc flap is visible from under the hood simply by removing the pollen filter. Have a helper initiate the self test while you're watching the flap. Even better, have a helper press the recirc button (in normal operating mode) and observe the flap operation.

The flap servos are pretty simple: they're just a 12VDC motor, geared down, with a 5K ohm potentiometer for position feedback. The Climatronic applies 12VDC of the appropriate polarity to drive the motor where it wants to. The Climatronic also provides regulated 5VDC power to the potentiometer (to either end of the resistance element) and simply monitors the wiper voltage to determine the flap position.

I've not heard many cases of servo failures, but sometimes the linkage will break or come loose. The recirc flap servo may be accessible with the glove box removed, but I've been fortunate enough to not had an issue with mine, so I'm not sure.

The Climatronic can also monitor the various temperatures, etc. (OBD mode). I'd suggest you monitor parameter 40, Evaporator Temperature--Actual Value. That should tell you if you have an actual refrigeration issue. If you do, you can probably get it repaired locally by a competent A/C shop. (Unlike so much on our cars, the refrigeration system seems to be pretty ordinary.) See other threads on PassatWorld regarding clogged dryers, etc.
 

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Discussion Starter · #5 ·
Well, rechecked the system since I 1st posted. I removed the pollen filter and had my wife operate the system. The recirc system seems to be working fine. 1 inner flap closed 1st then the outer flap closed afterwards. I did the self check on the system, then checked for codes. Found a lot more codes that the 1st time. It displayed "25B" and the following codes in sequence afterwards- 4F7, 4F8, 4FA, 318(?) and then displayed the 25B again with the 000 on the right side of the display. Does this make any sense? When I did the self test, it seemed like things (flaps, airflow, etc) were moving & working properly. Just blew heated hot air out the vents when I ran it afterwards.
 

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Discussion Starter · #7 ·
But the A/c cycles and has freon in it. The problem is, it blows heated air from the vents, not just warm air/outside air. Would be driveable at 50-60 degree temps, but heat blows all the time and windows down doesn't work when it's 70's and higher temps outside. When it's 30 and below, not enough heat to keep warm. When this problem 1st developed, the only code was the 4FA if I remember correctly.
 

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What is the value of parameter 40, evaporator temperature? (It's in degrees C, not F) It should be in the single digits before too long if the refrigeration is working, and around 3°C eventually.

If your refrigeration is "making cold" and you do indeed have a flap issue, you can look at the servo positions in the Climatronic OBD mode, as well. Parameter 26 is the temperature flap. You should see the value vary between the (-) limit (parameter 25) and (+) limit (parameter 27) as the flap moves. If that value varies as it should, that probably indicates a linkage issue. (Experiment with the recirc flap to see how they work, since it's easy to directly control.) There are a few plastic pieces, so breakage is certainly a possibility.

The temperature flap linkage is color coded red. I don't know if it's accessible without removing the dash. But if you can get your had on it, "stuck in cold" would beat "stuck in heat" for the next few months!

Can someone else can give some guidance on how to get to the temp flap?
 
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