# 2006 Beetle 2.5l radiator fan always running on high speed



## Beetle2006 (Oct 11, 2019)

Hi All,

New to the forum and fairly new to VW ownership.

My wife has a 2006 beetle with the 2.5l. The radiator coolant fan (single fan with integrated fan control module) runs on high constantly. It doesn't even need to be started, just turn the key to the run position and the fan starts running fast after 10 seconds. It does turn off when the key is turned off.

I get a P0480-004 code, coolant fan control circuit 1: electrical malfunction - no signal / communication.

I bought a supposedly tested fan from a junkyard, but it acts the same. Either the replacement is bad or I have something else wrong. I told them I would try troubleshoot more before returning it.

I built a breakout cable with connectors from a junkyard and measured the signals with my scope. This fan has a 4 pin oval connector - 12v power, GND and 2 smaller control wires. It appears the one small gauge wire must come from a controller in the car as when the key is turned to run it goes up to close to 12v with a square wave pulse train on it. When I disconnect it from the module the fan stops. When reconnected, the fan starts after 10 seconds.

The other small wire appears to be driven by the fan control module directly attached to the fan and part of the fan motor assembly. When the fan is energized this signal goes to about 12v and then drops in voltage a volt or 2 as the fan winds up in speed.

I found online that the coolant temp sensor affects the fan control, so I bought a new one and plugged it in, but that had no change in fan operation. Still runs full speed with key in run.

I found online that the intake air temp sensor also plays a part in fan speed. I used vcds to get a readout of intake air temp and it was off, but not crazy. It was reading 35 degrees Celsius (95 degrees Fahrenheit) when actual air temp was about 15 degrees Celsius (60 degrees Fahrenheit).

Does anyone know what the signals to / from the fan control module should be with the key in run? How about when the fan is running? Any suggestions as to how I can debug this or prove the used replacement fan is good or bad?

Thanks!


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## billymade (Jan 29, 2008)

These later fans, seem to be problematic and then, their replacement cost is particularly high, as noted, the fan controller is integrated into the fan assembly (VDO seems to be th oem for these VW fans). As always, start by looking up the trouble codes; on the ross tech wiki, which specifically geared towards VW/Audi repair, as they are the maker of your VCDS scan tool. 

http://wiki.ross-tech.com/wiki/index.php/16864/P0480/001152

The above link; maybe helpful, in basic areas to check, although it sounds like you maybe beyond that info? 

I don't know, if I can be much help; as to the specifics of your questions. Getting access to correct wiring diagrams and solid VW factory testing procedures or troubleshooting from eRWin or AllData/Mitchell1, could shed some light on how the system works and specific testing steps to take. Sine you have VCDS, doing some live data and output testing, might be helpful, to "see", what the ecu is seeing or what is occurring. 

Here are some free online service manuals; which may or may not be helpful: 

https://workshop-manuals.com/volkswagen/

Keep in mind, there has been a history; of members, struggling with the later fan system and finding the correct wiring diagrams and service info, provided by VW. 

Note: you mentioned the coolant temp sensor; again, this may or may not apply to you BUT many get the coolant temp sensors and the fan switch sensors mixed up. Typically, the fan switches are located in the radiator but the coolant temp sensor for the speedo/idiot light, is located in the coolant flanges, comes off the head. Best to find the VW factory code for the sensor and then, find which is which, where it is located. 

You are one of many; who struggle to figure out these cooling fan errors and malfunctions, if that is any consolation. I don't know, if I have been any help but keep us in the loop, as your testing/repairs move forward. Thanks.


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## Beetle2006 (Oct 11, 2019)

Thanks for the info Billymade.

I've got a couple new clues today. I went back to the junkyard and exchanged the fan I bought for another one. I hooked it up, and at first it seemed to act just like my old one and the first one from the junkyard. I realized though that when I start the engine with this one attached after 10 seconds it runs up fast (like my original), but a little bit later (maybe 30 seconds, I didn't time it) it appears to slow down for a few seconds and then goes back up again. It cycles like that one more time in another 30 seconds or so.

I had the heat / AC turned off, temp set to warm and air set to come out floor or dash vents and noticed my AC compressor clutch was engaged and spinning. Does the AC compressor in these run all the time or should it be off with the heater controls set as described? Could this be related to fan running on high all the time?


Thanks!


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## billymade (Jan 29, 2008)

The early new beetles (1998-2005), have a traditional Sanden brand a/c compressor with a clutch, that engages/disengages with the hvac controller/switches and then, after 2006 the new beetle became a odd combination of mark iv and mark v volkswagen platform car parts, that are shared with the golf, rabbit and jetta. I have noticed the mark v golf and rabbits use a newer clutch-less design a/c compressor and i believe the 2006 on new beetles, are the same; you might get the Sanden part # off of the compressor itself, then research the compressor to see if it is indeed clutch less (good info on the Sanden a/c parts site). You maybe on to something here but you might consider getting access to a Bentley manual or download the eRWin online access service info, to fully understand how the system works and this is setup, which may help you diagnose the fan issues.


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## Beetle2006 (Oct 11, 2019)

billymade said:


> The early new beetles (1998-2005), have a traditional Sanden brand a/c compressor with a clutch, that engages/disengages with the hvac controller/switches and then, after 2006 the new beetle became a odd combination of mark iv and mark v volkswagen platform car parts, that are shared with the golf, rabbit and jetta. I have noticed the mark v golf and rabbits use a newer clutch-less design a/c compressor and i believe the 2006 on new beetles, are the same; you might get the Sanden part # off if the compressor itself, then research the compressor to see if it is indeed clutch less. You maybe on to something here but you might consider getting access to a Bentley manual or download the eRWin online access service info, to fully understand how the system works and this is setup, which may help you diagnose the fan issues.


Thanks Billymade! After I posted I found a good post in the Audi area with a video on the Clutchless Variable Displacement Compressor. This must be what you are referring to. I'll try get the part number off the compressor and see what I can find.

I'm starting to wonder if there isn't something in one of the control modules that is telling the fan to run full. I wish there was a way to tell if that is the case.


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## billymade (Jan 29, 2008)

I worked on 2007 Rabbit that had. a bad a/c compressor with a stuck pressure valve; i was able to use vcds by ross tech and was able to view some status info, about the hvac system., you maybe able to as well: 

https://www.google.com/search?q=vcd...test&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari


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## Beetle2006 (Oct 11, 2019)

I'll see if I can try that tomorrow. Need to do some googling to figure out what to try view with VCDS.

I looked up the AC compressor on parts.vw.com and it looks like it is common with newer Jettas, Passats, Golfs and Rabbits (~2005 - 2013), so it's likely I have the variable displacement compressor.


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## billymade (Jan 29, 2008)

That is what i would assume; check the above link, for some videos showing vcds, being used, accessing and diagnosing the hvac system.


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## 2002sportside (Aug 31, 2003)

Beetle2006, did you ever figure this out? Chasing the same issue now...


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## billymade (Jan 29, 2008)

Is the problem, exactly the same and have you done any testing or scanned for trouble codes? :screwy:


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## 2002sportside (Aug 31, 2003)

Same code, and I am as far as he was in troubleshooting with the same results so far, which is why I asked.


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## RebuilderGuy (Dec 23, 2020)

2002sportside said:


> Same code, and I am as far as he was in troubleshooting with the same results so far, which is why I asked.


Have you figured out the problem? I’m having the same issue with my 2015 VW golf mk7.


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## Cine Emmanuel (Apr 23, 2021)

I got the new beetle 2008 with the same problm the ac still work i replaced the ect bt the fan still always runing on high speed


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