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2007 Continental GTC Fans Start Running After Car Is Locked

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2007 Continental GTC Fans Start Running After Car Is Locked

 
  #16  
Old 04-21-2019, 10:57 AM
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BTW, just as a point of mention, in another thread, I was explaining how the fan control module worked, receiving puls signals from the ECU. A look at your first two graphics, when these measuring blocks were recorded, the ECU was commanding a 94.1% duty cycle from both fans and in both cases. If the fans themselves do not run or the FCMs are bad, the ECU doesn't know that, but it continues to signal the fans with a specific duty cycle commensurate with ECTs. In these cases, 105/107C. As the fans continued to fail to respond, the motor eventually overheated. Also, no manufacturer I know of ever commands 100% duty cycle, because of the very high amps these fans use.

Here is a table of a typical EMS the ECU draws from to determine fan speeds within operating range:



When AC is on, and since this taxes engine temps in a different way, the ECU defaults to a fan speed based on AC KPa. This is "off topic" from your issues, but hopefully just a little more background info on what's going on with these fans.

 

Last edited by BWings; 04-21-2019 at 11:06 AM.
  #17  
Old 04-21-2019, 12:38 PM
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Originally Posted by BWings View Post
So, you have a basket full of faults. As I've perused them, you have several "electrical intermittents" along with some specific component failures, a couple of which point to the fans. Then there is one fault I consider a priority. It is the U-code. U-codes are faults in the CANBUS network, either in intermittents or complete failures. If the CANBUS has faults, it could be generating the failures/faults in component specific failures.

When I'm faced with this, the U-Code(s) must be fixed first. Then clear codes, run the car, see what returns. A single U-Code fix sometimes solves everything else.

Some of the codes in your list have a common check/remedy. That is, check the connection integrity to the ECUs. As much as this comes up out of the clear blue sky on this forum, this is the one good example where it is warranted to remove the cowl, see what's going on at the ECUs, the fuse box, the connectors surrounding the ECUs. Visual will tell you a lot. Look for common water damage to the cabling and components including the fuse box.

Once you get past this, especially if you've found something there, correct it, then clear codes, see if the coolant issues automatically correct (correct because the intermittent communications on the CANBUS have been fixed).

After you reestablish integrity on the communications (CANBUS and intermittent electricals), then tackle the fans issue. Codes are directing you to failed fan(s) or/and FCMs. BUT, I would not start here, only end here after the U-code fixes. The worst thing you can do is proceed in all directions at the same time.

Best,
Also Mr. BWings has duly warned, past stickies the importance of being grounded when tinkering around the ecu's and electronics. I've always used a non conductive floor mat, wear rubber soled shoes and rubber gloves. However the idea of also having a grounded wrist strap sounds like a sage caveat.

THX
 
  #18  
Old 04-21-2019, 12:44 PM
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Thanks BWings - it's all pointing to faulty FCMs but i'm going to spend some time going from A>B>C to confirm the diagnosis. I'll also supply 12v direct to the fans to ensure the motors are serviceable, but i suspect they will be.

Could i scope the input to the FCM from the ECU to see if indeed the signal is getting to the FCM from the ECU?
 
  #19  
Old 04-21-2019, 06:57 PM
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Originally Posted by neiloakley View Post
Thanks BWings - it's all pointing to faulty FCMs but i'm going to spend some time going from A>B>C to confirm the diagnosis. I'll also supply 12v direct to the fans to ensure the motors are serviceable, but i suspect they will be.

Could i scope the input to the FCM from the ECU to see if indeed the signal is getting to the FCM from the ECU?
I cannot say for certain on VAG, but on most of these systems, the ECU signal is completing a ground (not a +5v), so you need to be aware, not to feed the signal with a +v. For the fans, they need to be powered +12v full time (only way they can run ignition off). Jumpering the two heavy cables in the harness going to the fans complete the circuit and what is being switched in the FCMs. If the fan motors are OK they should run with direct 12v.

If the fan motors turn, there are only three other possibilities:
1. Bad FCM
2. Bad, defective wiring, fan grounding especially check for a bad signal wire back to the ECUs.
3. Bad ECU
 

Last edited by BWings; 04-21-2019 at 07:02 PM.
  #20  
Old 04-22-2019, 02:00 PM
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So todays update as follows:

Replaced a blown fuse 12 in the engine bay fuse box - it's a 10A that controls the Rad Fans although i'm not sure which specific aspect of the system it is protecting.

Once that had been replaced, the fans began to function as expected increasing in speed with radiator outlet temperature / engine coolant temperature. The duty cycle and fan speed also increased as expected with the AC turned on. Left the car idle for around 40 minutes and fans were doing a great job of keeping the ECT at around 93/94 degrees C.

Problem is, I am now back to the original fault. After i had performed the above test, i turned of the ignition and locked the car. it was 9 minutes later that the fans started up and continued to run at full speed for about 20 seconds.

So, something is causing the fans to trip in well after the engine is shut down and the ignition turned off. And something also blew the fuse 10A fuse 12.

Latest VCDS scan attached, but doesn’t show anything i would consider t be linked or significant.
 
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  #21  
Old 04-23-2019, 06:41 AM
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If you're using the car, do another scan. See if anything returns, especially the U-code. I kinda disagreed with you on your post #14. Deleting a bunch of codes assuming they're a result of a low battery is not what I would have concluded, but if you understand what U-Codes govern, you're describing a recurring issue that is on the lines of a data intermittent failure(s). An intermittent code (failure) especially something like a CanBus intermittent might not immediately reappear; instead, might take certain conditions or a combination. I'm betting you haven't seen the end of the U-code.
 
  #22  
Old 04-23-2019, 07:13 AM
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Here is a suggestion for you.

Earlier it was discussed to examine the integrity of the electronics surrounding the ECUs, including connections and the engine fuse panel.

Take a look especially at the fusebox. See if there is evidence of water ingress (even if dry now).

Check the following:

Relays:
33 - EMS Current Circuit #1
35 - Ignition
38 - Engine Management System Accessories
40 - EMS Current Circuit #2

Finally, the large smoothing capacitor #34. This capacitor (as capacitors do) holds/stores a charge. and is used in battery management in the Bentley. it smooths out voltage ripple between the alternator and the main battery. Without this capacitor (in the event it fails), the ripples can lead to electrical faults.

Any of these components, if failed, MIGHT be causing your fan restart after ignition shutdown.
 
  #23  
Old 04-23-2019, 09:01 AM
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Neil , iam with Bwings on the engine fuse box susceptibility to damp and the route of all evil with these cars .
Like most newbys on here I did find this forum informative and figured out the whole scuttle thing was a problem easy to sleepwalk into .
Mines garaged when I can but itís exposed in the winter to alpine weather , snow etc often when parked outside that needs clearing .
Wheres it gonna go ? Whereís the melt gonna go ?
I did a thread recently on ď scuttle drains maintenance ď

i,am on my third year now and early on I had a minor issue that necessitated removal of the fuse box cover in the scuttle .
I was shocked how exposed it was , those multi pin connections sat on top totally exposed and crucially the flat top nature of the lid .
what I mean is water could ,depending on the parking angle / gradient of the car basically run back , to the side , any direction and if unlucky find in a Sodís law way any poor lid seal .
lets face it the lid and itís seal are flaky at best and thereís a knack to properly replacing it .
How do you really know itís water tight ?

So with a bit of fire proof cloth that easily adapts I cable tied a cover to keep it dry , give it some weather protection .


Tie wrapped .

Scuttle cover in place


The main ECUs are tucked right under and I feel have adequate weather protection from rain / snow melt unlike the ď fuse ď box and the multi pin connect s sat on top .
 

Last edited by John Fiammetta; 04-23-2019 at 09:05 AM.
  #24  
Old 04-23-2019, 09:05 AM
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Originally Posted by John Fiammetta View Post
Neil , iam with Bwings on the engine fuse box susceptibility to damp and the route of all evil with these cars .
Like most newbys on here I did find this forum informative and figured out the whole scuttle thing was a problem easy to sleepwalk into .
Mines garaged when I can but itís exposed in the winter to alpine weather , snow etc often when parked outside that needs clearing .
Wheres it gonna go ? Whereís the melt gonna go ?
I did a thread recently on ď scuttle drains maintenance ď

i,am on my third year now and early on I had a minor issue that necessitated removal of the fuse box cover in the scuttle .
I was shocked how exposed it was , those multi pin connections sat on top totally exposed and crucially the flat top nature of the lid .
what I mean is water could ,depending on the parking angle / gradient of the car basically run back , to the side , any direction and if unlucky find in a Sodís law way any poor lid seal .





















lets face it the lid and itís seal are flaky at best and thereís a knack to properly replacing it .
How do you really know itís water tight ?

So with a bit of fire proof cloth that easily adapts I cable tied a cover to keep it dry , give it some weather protection .


Tie wrapped .

Scuttle cover in place
What a fantastic idea, simple but very affective ...
 
  #25  
Old 04-23-2019, 09:07 AM
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Which begs the Question , Neil is your car or has it been parked outside ?
And if so what gradient if any ?
 
  #26  
Old 04-23-2019, 09:24 AM
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Red circle is a drain + Thx Bentley The bigger blue arrows are potentially where water can get in and errr fall directly on the fuse box , Thx again Bentley.

My cover protects this area from damp .
 
  #27  
Old 04-23-2019, 01:02 PM
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Yes the car is parked outside, on flat ground. When i opened that fusebox yesterday there was no evidence of any current or historic water ingress. The scuttle gets cleaned every time the car is serviced.

However, I will recheck it as soon as time permits. But for now my primary route of investigation is in relation to the following fault on the CAN Gateway:

1 Fault Found:
00470 - Company Comfort Databus in Single Wire
012 - Electrical Fault in Circuit

It would seem the CAN twisted pair is broken somewhere in the car, possibly between the CAN Gateway and the Wiper Control Module (similar fault there). i'll also check to the door modules as this seems to be a common place for wires to break. This broken CAN wire can result in modules not sleeping, and if ECU isn't asleep then it 'could' turn the fans on. Or is that too much of a stretch?
 
  #28  
Old 04-23-2019, 02:20 PM
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Originally Posted by neiloakley View Post
Yes the car is parked outside, on flat ground. When i opened that fusebox yesterday there was no evidence of any current or historic water ingress. The scuttle gets cleaned every time the car is serviced.

However, I will recheck it as soon as time permits. But for now my primary route of investigation is in relation to the following fault on the CAN Gateway:

1 Fault Found:
00470 - Company Comfort Databus in Single Wire
012 - Electrical Fault in Circuit

It would seem the CAN twisted pair is broken somewhere in the car, possibly between the CAN Gateway and the Wiper Control Module (similar fault there). i'll also check to the door modules as this seems to be a common place for wires to break. This broken CAN wire can result in modules not sleeping, and if ECU isn't asleep then it 'could' turn the fans on. Or is that too much of a stretch?
On an 00470 and a 2005/06 MY, the driver's door module was a common culprit. They were supposed to have been better after that, but the door module might be the module waking back up again after shutdown. Still awfully strange it would cause cooling fans to run, but based on what else it wakes up.....It's possible the ECUs come back online when the door wakes, and engine temps will definitely be above 107*C if the engine ran to op temps just 5/7 mins before....a bunch of "if/thens" but worth some investigation. Go in and isolate it, clear codes, go through the routine again, see if 470 comes back w/o the DS door module online.
 
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Old 04-23-2019, 04:01 PM
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I've only had my 2004 for 3 weeks and this may not be related to the OP's problem but mine only come on when the front bumper is off and the bumper wiring is unplugged ( parking sensors and outside temp sensor).

also whenever I write a car related part on my posts on this site the word turns blue and creates a link. Any ideas as to why? This has just happened when I wrote the 3 letter word starting with F middle letter A and last letter N !!!??
 
  #30  
Old 04-23-2019, 04:03 PM
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Originally Posted by UKGT View Post
I've only had my 2004 for 3 weeks and this may not be related to the OP's problem but mine only come on when the front bumper is off and the bumper wiring is unplugged ( parking sensors and outside temp sensor).

also whenever I write a car related part on my posts on this site the word turns blue and creates a link. Any ideas as to why? This has just happened when I wrote the 3 letter word starting with F middle letter A and last letter N !!!??
This happened to me this morning, no idea why ...
 

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