Thermotop C wont stop running

[pastyman]

Hi, I have a problem with the Thermotop C engine coolant pre heater in my 2009 Cali. It has recently started turning on (or the sound of the fan at least) when the van is unlocked. This is when the temp is usually around 7 degrees but it seems a bit random. Anyway, if I then lock the van again without ever putting the key into the ignition the TTC keeps running. It has done this several times and I have ended up pulling fuse #29 to stop it, the longest I left it was 90mins before I decided it would just flatten the starter battery eventually. If I start the engine and then switch off again it still keeps going. If I drive until the engine is warm....it will then have stoped and not be running when the engine is turned off. I have had the van looked at by my local VW Dealer and they could not find any fault codes and suggested it is normal operation and didn't know what else to check, which it isn't as it hasn't done this in the 10 years I have owned it.

So I am not sure where to go from here.....obvisously this isn't a specific Cali issue as lots of T5s have the TTC fitted to pre warm the engine coolant and get the heaters working quicker on cold days. I don't suppuse anyone has experienced this issue and had a resolution?

 

[Alied]

Hi, I have a problem with the Thermotop C engine coolant pre heater in my 2009 Cali. It has recently started turning on (or the sound of the fan at least) when the van is unlocked. This is when the temp is usually around 7 degrees but it seems a bit random. Anyway, if I then lock the van again without ever putting the key into the ignition the TTC keeps running. It has done this several times and I have ended up pulling fuse #29 to stop it, the longest I left it was 90mins before I decided it would just flatten the starter battery eventually. If I start the engine and then switch off again it still keeps going. If I drive until the engine is warm....it will then have stoped and not be running when the engine is turned off. I have had the van looked at by my local VW Dealer and they could not find any fault codes and suggested it is normal operation and didn't know what else to check, which it isn't as it hasn't done this in the 10 years I have owned it.

So I am not sure where to go from here.....obvisously this isn't a specific Cali issue as lots of T5s have the TTC fitted to pre warm the engine coolant and get the heaters working quicker on cold days. I don't suppuse anyone has experienced this issue and had a resolution?

There's a member on the T6 Forum called oldiebut goodie. He's very knowledgeable on Webasto and Eberspacher.

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[WelshGas]

Hi, I have a problem with the Thermotop C engine coolant pre heater in my 2009 Cali. It has recently started turning on (or the sound of the fan at least) when the van is unlocked. This is when the temp is usually around 7 degrees but it seems a bit random. Anyway, if I then lock the van again without ever putting the key into the ignition the TTC keeps running. It has done this several times and I have ended up pulling fuse #29 to stop it, the longest I left it was 90mins before I decided it would just flatten the starter battery eventually. If I start the engine and then switch off again it still keeps going. If I drive until the engine is warm....it will then have stoped and not be running when the engine is turned off. I have had the van looked at by my local VW Dealer and they could not find any fault codes and suggested it is normal operation and didn't know what else to check, which it isn't as it hasn't done this in the 10 years I have owned it.

So I am not sure where to go from here.....obvisously this isn't a specific Cali issue as lots of T5s have the TTC fitted to pre warm the engine coolant and get the heaters working quicker on cold days. I don't suppuse anyone has experienced this issue and had a resolution?

I would presume a temperature sensor, that measures the external temperature or coolant temperature is playing up.

Have you tried the T4 / T5 forum.

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[pastyman]

Thanks for the quick replies. I had thought it might just be one of the temp sensors but with the dealer not finding any fault codes and not offering any further suggestions it left me a bit stumped. I did do a search of the T5 forum and found some posts about issues with the TTC , one turned out to be a wrong fuse and another the chap took the webasto apart and resoldered the control board. I will try posting my question on there and see if anyone has any further suggestions which I could then get the van center to look at, swapping out a couple of temp sensors might be a start.

 

[Lez99]

Hi, I seem to be having the very same problem you are describing, and I'm suspecting a loose connection or a problematic sensor of some sort. Diagnostics shows no error codes.

Did you manage to resolve your problem ? What solution did you find ?

 

[WelshGas]

Hi, I seem to be having the very same problem you are describing, and I'm suspecting a loose connection or a problematic sensor of some sort. Diagnostics shows no error codes.

Did you manage to resolve your problem ? What solution did you find ?

Word of advice. When replying to a Post, if you don’t use the “Reply” button then the original Poster does not get a notification and whether he sees the post is dependant on him checking the thread each time he visits.
In this case @pastyman has not visited the Forum since April 19 2021.

 

[Lez99]

Thanks ! I didn’t know that.