Seemingly random total shutdown of CCU (climate control unit)
Thread Starter
Three Wheelin'
Joined: Nov 2012
Posts: 1,952
Likes: 389
From: connecticut
Seemingly random total shutdown of CCU (climate control unit)
Hello all
I've been waiting on posting this to gather more data but tonight put me over the edge. Went out with the a/c on, fan speed 2, headlights on, etc. Everything normal. Drove ten minutes, parked, when I turned the car back on the CCU was dead. No response to fan speed dial or any other buttons. This has happened to me now and again but I've always been able to coax it back to life by seemingly random inputs - adjusting heat all the way hot/cold, pressing recirc, adjusting fan speed etc. Sometimes even turning the car off/on has produced results. This time, nothing.
I have replaced just about every fuse in the car and last time I had the CCU out I made a point of using some deoxit on its connectors. When its working, it works 100%. Only errors regard one of the mixing flaps (error has been there on and off for years) and sometimes the interior fan, which I replaced with a similar denso and I can hear working correctly, and shutting down correctly.
Help!
I've been waiting on posting this to gather more data but tonight put me over the edge. Went out with the a/c on, fan speed 2, headlights on, etc. Everything normal. Drove ten minutes, parked, when I turned the car back on the CCU was dead. No response to fan speed dial or any other buttons. This has happened to me now and again but I've always been able to coax it back to life by seemingly random inputs - adjusting heat all the way hot/cold, pressing recirc, adjusting fan speed etc. Sometimes even turning the car off/on has produced results. This time, nothing.
I have replaced just about every fuse in the car and last time I had the CCU out I made a point of using some deoxit on its connectors. When its working, it works 100%. Only errors regard one of the mixing flaps (error has been there on and off for years) and sometimes the interior fan, which I replaced with a similar denso and I can hear working correctly, and shutting down correctly.
Help!
Thread Starter
Three Wheelin'
Joined: Nov 2012
Posts: 1,952
Likes: 389
From: connecticut
I found this thread and will be going thru it...
https://rennlist.com/forums/964-foru...se-help-2.html
https://rennlist.com/forums/964-foru...se-help-2.html
Former Vendor
Joined: Jul 2018
Posts: 1,093
Likes: 180
From: SoCal
Hello all
I've been waiting on posting this to gather more data but tonight put me over the edge. Went out with the a/c on, fan speed 2, headlights on, etc. Everything normal. Drove ten minutes, parked, when I turned the car back on the CCU was dead. No response to fan speed dial or any other buttons. This has happened to me now and again but I've always been able to coax it back to life by seemingly random inputs - adjusting heat all the way hot/cold, pressing recirc, adjusting fan speed etc. Sometimes even turning the car off/on has produced results. This time, nothing.
I have replaced just about every fuse in the car and last time I had the CCU out I made a point of using some deoxit on its connectors. When its working, it works 100%. Only errors regard one of the mixing flaps (error has been there on and off for years) and sometimes the interior fan, which I replaced with a similar denso and I can hear working correctly, and shutting down correctly.
Help!
I've been waiting on posting this to gather more data but tonight put me over the edge. Went out with the a/c on, fan speed 2, headlights on, etc. Everything normal. Drove ten minutes, parked, when I turned the car back on the CCU was dead. No response to fan speed dial or any other buttons. This has happened to me now and again but I've always been able to coax it back to life by seemingly random inputs - adjusting heat all the way hot/cold, pressing recirc, adjusting fan speed etc. Sometimes even turning the car off/on has produced results. This time, nothing.
I have replaced just about every fuse in the car and last time I had the CCU out I made a point of using some deoxit on its connectors. When its working, it works 100%. Only errors regard one of the mixing flaps (error has been there on and off for years) and sometimes the interior fan, which I replaced with a similar denso and I can hear working correctly, and shutting down correctly.
Help!
the X power at the fuse may have an intermittent connection. Seen that problem twice in the last 6 months at two different Porsche shops. They thought they had bad CCUs.
Rennlist Member
Joined: Apr 2004
Posts: 2,570
Likes: 538
From: Oslo, Norway
It is a known issue that the fuse holders loosen over the years, and can make intermittent contact.
As Loren mentions, you have to check all power supplies, see this web page for details on this.
This could also be an internal CCU issue, the internal power relay solderings fail over time.
Cheers,
Tore
As Loren mentions, you have to check all power supplies, see this web page for details on this.
This could also be an internal CCU issue, the internal power relay solderings fail over time.
Cheers,
Tore
Last edited by ToreB; Aug 24, 2022 at 04:17 PM.
Thread Starter
Three Wheelin'
Joined: Nov 2012
Posts: 1,952
Likes: 389
From: connecticut
Thanks All. I have done some work on the backside of the fuse box and will check for intermittency. Is it fair to summarize that only fuse number 17 effects the CCU and nothing else? In other words intermittency in any of the other fuses mentioned would affect other portions of the car
Track Day
Joined: Apr 2022
Posts: 16
Likes: 0
Check this guide to further diagnose the issues in the CCU: https://cdn.shopify.com/s/files/1/25...f?v=1616075561
IHI KING!
Rennlist Member
Rennlist Member
Joined: Aug 2001
Posts: 13,400
Likes: 230
From: Nashua, New Hampshire, USA
Thanks All. I have done some work on the backside of the fuse box and will check for intermittency. Is it fair to summarize that only fuse number 17 effects the CCU and nothing else? In other words intermittency in any of the other fuses mentioned would affect other portions of the car
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Thread Starter
Three Wheelin'
Joined: Nov 2012
Posts: 1,952
Likes: 389
From: connecticut
Thanks Rob. I did check, and just in case, replace fuse #1. I've been thru the current draw issue a few years back and my car is now drawing very very little, working as intended.
I think the issue is with intermittency inside the unit or at another connector I haven't located yet.
I think the issue is with intermittency inside the unit or at another connector I haven't located yet.
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