Comfort module/voltage regulator issues

[zrock1]

Hi all, 

 

MK2 2009/ petrol 1.4 BXW  - i have the old or the first fuse plate. Like this one - https://www.autogenius.info/skoda-fabia-2009-fuse-box-diagram/   

 

On Fuse 22 i have 200mA parasitic drain. I am not able to find where it comes from, but it take my battery down for less then a week, and i am sick if it. 

I've fully removed my radio unit as it looked like was not well connected (its aftermarket cheap one...) 

 

Can you please tell me where i can find - 

 

1) The voltage regulator - and what on earth that thing is doing for the car?? Sorry probably stupid question...

2) I think my comfort module go rogue and its not turning off always properly the power. I think after 10 to 15 i hear a ticking sound from it and power is "turned off"... eventually. 

3) i  have a parking aid, i need access to that module too - but i can't find it. The problem with this one is - the vag-com is not able to communicate with it, it doesn't appear at all.  

 

Thanks a lot for your time and help! 

 

 

 

[Breezy_Pete]

When you say voltage regulator, do you mean "vehicle voltage control module" as mentioned on that fuse diagram? If not, what? There is a voltage regulator within your alternator, which keeps the system voltage at about 14.5V as far as possible while the engine is running.

 

If "vehicle voltage control module" is what you mean, it's the same thing that you are calling Comfort Module, and controls much of the equipment in and beyond the cabin, such as interior lighting, windscreen wipers, direction indicators, horn, etc.

 

How are you measuring the parasitic drain through fuse 22? Current measurement with meter in place of fuse, or (mV) voltage measurement across the fuse with it in place? The latter is better as it doesn't require interruption of the circuit. 

 

It's normal for the interior light relay (inside Comfort module) to remain energised for some time (default 30 minutes I think?) even after the lights go off, so you need to measure the current after that 30 minutes. In my experience this still shuts off OK with the door open to allow access to the fusebox. Just don't close and then re-open the door.

 

Have you replaced any bulbs in the cabin (or elsewhere) with LED types? 

[zrock1]

To clarify - If "vehicle voltage control module" is what you mean - Correct !  My voltage regulator is brand new and shows 14.6-8V when engine is running. Also i think my alternator is working well now after it was "refurbished". I have brand new battery - FIAAM 65Amps and its checked too... 

 

How i measure - car is fully locked and everything is turned off (to the best possible way - simply all buttons/switches are off) for about 45min. I do NOT remove the fuse just checking with meter - on 200mV reads - consumption of 02.2mV... 

I can tell that after 20min you can hear a distinguishable "click" from just behind the fuses and drain drops to 01.1mV that is still a lot around 100mA.... 

 

No lights or any electrical equipment changes since i have the car...Radio is checked 0A there.

 

 

[Breezy_Pete]

I think that 100mA drop in consumption when you hear the click maybe means the problem isn't anything to do with the interior light relay.  There might still be a fault in the control unit, but several other units might be the cause too.

 

I think, but don't know, that the parking aid control unit will be behind some trim in the trunk/boot area. That sounds like a good thing to disconnect to see  if that alters the behaviour.

 

[J.R.]

Completely disconnect the aftermarket radio, unless you change to a higher revision number CAN gateway then it will not shut down as it does not get the correct sign off signal from the radio, the radio is shutting down hence no current but the CAN gateway cannot, the 100ma sounds about right for that problem.

[zrock1]

@ Pete - i am on the same page, i think this is the only one thing that left, also i found its aftermarket part...one of the reasons maybe there is completely no communication with that module... 

 

@ J.R - Radio is disconnected also ... Strange thing about the radio  - its on its own fuse, and it works correctly. BUT when car is completely off, radio still can work. That looks like a factory decision as if i remove the fuse - radio is dead right away. 

 

My car is on K-line only - no CAN. here...

 

 

[rum4mo]

Maybe a "red herring", but I had a problem with the battery draining on a 2009 SEAT Ibiza 1.4 BXW, and after exhausting all, in my mind possible reasons, came to the conclusion that it was a BCM coding issue, eventually I found a SEAT dealership that was willing to check that car and submit a "global help" technical request to SEAT "mothership" and that resulted in them being directed to a BCM S/W patch that had been raised back in maybe 2011 and so lost from the dealership's "sight" as it was so old and considered that all cars affected would have already been submitted complaining about this issue years ago. Applying that BCM patch to that car solved that problem.

The main reason maybe that that SEAT dealership had been able to help me where another SEAT dealership could only replace possible faulty assemblies, would be down to them having to discover this issue with a similar aged VW Polo 1.4 BXW and solving it, very little is known about this issue or the S/W patch offered back in maybe 2011.

The reason that I am posting is that all of these cars are 2009 with a 1.4 BWX engine so possibly also have the same p/n of BCM fitted - and the 2 cars I mentioned did not show any logged faults, they just drained the battery too quickly if not used daily or every other day.

 

Just something to consider if no actual faults can be found elsewhere on that car.

[zrock1]

Thanks a lot for this info -very useful, can you just confirm what BCM means? I can't get all terminology yet? Is that the main computer or something?

 

And to clarify - you mean coding that can be done on the module with VAG-COM lets say, or you mean - software/firmware update from the main dealer? 

Edited 29 January, 2022 by zrock1

[rum4mo]

BCM is the module that controls some of the power distribution and it is it that forces "unwanted" supplies to sleep to minimise battery drain as well as switching of some or most loads.

 

No it is not coding that can be done using VCDS, it is the firmware that gets re-flashed and so when you check that module with VCDS the S/W issue gets changed after a re-flash.

 

Edit:- being able to identify any changes to S/W is quite handy as you can see if the dealership has carried out updates during servicing of cars still under warranty. I asked the service receptionist at the first SEAT dealership I took that car into and he "confirmed" that the techs do not know the S/W changes or if they have been successfully made and the only way that they keep track of S/W updates is by logging them locally - that must be BS as the displayed present S/W issue/build must or should mean something to them if VW Group bother about configuration control. So in answer to my question to them "don't you know if controllers have been updated already as you must need to be able to do that so that you know what route to take to solve known issues?"  they just said "no, if in doubt we would just request that S/W update and the online machine only confirms that an update has been passed down to that controller". Sounds like fun but I'd hope the workshop techs know a lot more than that!

Yes, very annoying having a car and wondering if it will start after not being used for a few days, after the first unsuccessful fix, where just the clockspring assembly was replaced because they thought it might be causing this problem, we went away on holiday and left this car at the airport carpark, but I put a jump pack in the car, on our return, the car unlocked and almost started once, but not the second time, I trusted it to start and released the key too soon, but the jump pack worked! Sorting this car out became a battle that I was not willing to give up on!

Edited 29 January, 2022 by rum4mo

[zrock1]

Thanks a lot for the feedback - now question of the day:

 

Some modules are reporting S/W and H/W versions - like this one 

 

Address 01: Engine        Labels: 03C-906-024-BXW.lbl
   Part No SW: 03C 906 024 B    HW: 03C 906 024 F
   Component:  MARELLI 4HV        2491  
   Revision: --H11---    Serial number: SKZ7Z0I5385482
   Coding: 0000071
   Shop #: WSC 00808 123 00808
   VCID: 1D62D66CBABF373EA77-5160
   VINID: 91D4974C215A1490C11C92460039C156FA

 

 

But there is no information from the others like - 

 

Address 08: Auto HVAC        Labels: 6Q0-820-045-V1.clb
   Part No: 5J0 820 045 
   Component: Klimaanlage        X0850  
   VCID: 62275C5F931699118F5-5160

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect.        Labels:. 6Qx-937-049-C.lbl
   Part No: 6Q1 937 049 F
   Component: 0000 BN-SG.         2S36  
   Coding: 25742
   Shop #: WSC 13765  
   VCID: 3E0314CB23427115AFD-5160

No fault code found.

 

Address 46: Central Conv.        Labels:. 6Q0-959-433.clb
   Part No: 5J0 959 433 A
   Component: 05 Komfortgerбt     0001  
   Coding: 00019
   Shop #: WSC 13765  
   VCID: 3116FEB0EF03BFAA07F-4B1E

 

So how i can find out if i visit the Stealship - if they actually updated the module? What i am think now is - if there is not S/W present from the scan, actually the module is not "update-table" ?? 

 

Correct me if i am wrong?

 

Steve S.

 

[Breezy_Pete]

There's probably an original software version printed on the case. I wonder if @rum4mo knows what his originally was and what version they updated to?

There must be hundreds of thousands of these units out in the wild so it must be specific to a particular software version number, I'd think.

I speculate that the number in the red rectangle is the SW version this unit was born with:

 

[rum4mo]

Module 09, on your car is an earlier version of Central Electronics than that on the 2009 SEAT Ibiza, later units were given the description Body Control Module, ie BCM but its task is still the same although the later BCM contained a couple of subsystems, so maybe the question is, did VW Group slightly mess up with the built in controller in all these Module 09 at that period in time, and so late 6Q1 937 049 F shared similar issues as 6R0 937 087 B.

 

Back to "how can you tell what build level,  issue a Module 09 Central Electronics is currently at from scanning it?" - it is the 4 digit group at the right hand side of the "Component : " line, which in your case is "2S36".

 

Edit:- sorry it has taken so long to wind my brain/memory back 5 years and find print outs of "before" and "after" for that late 2009 SEAT Ibiza which was sold on in August 2019.

Edited 31 January, 2022 by rum4mo
added bits, corrected spelling/word.

[zrock1]

HI all, i've check'ed everything i can easily reach - connected to that fuse... and the result is disappointing. It's NOT the radio or the parking aid, I still have the parasitic drain... No errors from the diag made with HEXv2 latest version 21.9... 

 

So Fuse 22 in my car - 

Operating controls for the heating, control unit for air conditioning system - I dont know how to check but i have manual control i.e i dont have climatronic -  just display knobs. 

parking aid,- Not even connected here... i checked and its not the 3rd party added "Aid" ...

instrument cluster,  - no clue how to check it..but i doubt its the cluster... 

steering angle sender, - nop 

ESP, - no clue how to check but i assume i would receive an error for that system.... 

vehicle voltage control unit - 

 

I have 5J0 959 433 A is it possible for somebody to tell me what is the difference with 5J0 959 433 B ?

 

I will check with Skoda stealership if i can update the software or change this part, the problem is i have no clue how to make sure this part is the "Perpetrator" 

 

Thanks! 

[Breezy_Pete]

Central convenience module isn't in that list of things supplied by fuse 22, but the suffix B version doesn't seem to be compatible with suffix A, judging by its non-appearance in the short list of equivalent part numbers here: https://www.skoda-parts.com/spare-part/5j0959433a-central-control-unit-24088.html

 

I'd be tempted to extract the voltage control unit (the one I pictured above) from the car, open it and examine for any signs of damaged components.

On the earlier versions (suffix C, D) there was a surface mount capacitor that sometimes seemed to burn out, and cause current drain problems. Maybe the suffix-F has inherited this genetic flaw.

 

[Breezy_Pete]

Took me ages to find these pictures!

https://www.briskoda.net/forums/topic/490993-fabia-vrs-wipers-not-working/?do=findComment&comment=5514418

 

[zrock1]

You are correct... and i am confused now, as voltage control is brand new, also the power drain was present even after the voltage control was changed. (i had an issue with the alternator giving me 12.9-13V when car is on... now its 13.8-9V -so it was refurbished that included a new voltage control). 

 

I was thinking about the Central convenience module as it should "turn off" all the consumption eventually... 

 

 

[Breezy_Pete]

Vehicle voltage control unit is not the the thing on the alternator, it's a name that Skoda decided to call the Central Electronics control unit in early mk2 Fabia,  (not the Central Convenience unit, that's another)

Voltage regulator = part of alternator that should be keeping system voltage around 14.3V

 

Vehicle voltage control unit = VCDS address 09 = J519 in wiring diagrams = Onboard supply control unit (what Skoda called it in mk1 Fabia) = BCM (name for it in later mk2s) = what I have pictured in linked post with burnt capacitor,

it lives above the accelerator pedal on RHD cars, above clutch pedal on LHD.

 

Central convenience unit is a different module (VCDS address 46; J393 in wiring diagrams) which lives nearer to the centreline of the car, it deals with locks and alarm mostly. I don't see any evidence for its involvement in your problems, unless I missed something.

 

[zrock1]

Thanks a lot! You are the best, i will keep walkin! 

 

Address 09: Cent. Elect.        Labels:. 6Qx-937-049-C.lbl
   Part No: 6Q1 937 049 F
   Component: 0000 BN-SG.         2S36  
   Coding: 25742
   Shop #: WSC 13765  
   VCID: 3E64FFA4C8258A6A54D-5160

No fault code found.

 

Here it is - i will check it ! 

 

Edited 7 February, 2022 by zrock1

[zrock1]

To keep you posted on the problem - 

 

So i spoke with my local stealership and they were unable to verify the scan i posted here... It turns out the actual picture is slightly different - 

 

Address 09: Cent. Elect.        Labels:. 6Qx-937-049-C.lbl

   Part No: 6Q1 937 049 F -    What appears from HEX V2 scan 

   Part number by Skoda - 6Q0 937 049 FZ0R   = What the Shop told me this module should be actually... 
 

 Component: 0000 BN-SG.         2S36  
   Coding: 25742
   Shop #: WSC 13765  
   VCID: 3E64FFA4C8258A6A54D-5160

No fault code found.

 

I am not able to take it out for now, as the car will become unusable, and...i dont have the time now. 

Price that was provided from the stealship is outrageous, (~500 Euros) and i am afraid looking at this parasitic drain its 80% from the module...Second hand in this case is also very risky as it can be the same case. Not to mention that i am not able to find the exactly the same code, if anyone here can provide me with a list of "Compatible" codes would be very nice.

 

What makes me think its the module is the reason that after 2 hours of completely lock'ed car - drain remains the same, so it's not putting to sleep properly something or its simply not regulating the voltage properly. 

 

 

 

[Breezy_Pete]

It has no role in regulating voltage, it just switches things on and off, and manages the CAN and diagnostic communications. Vehicle voltage control module was the most confusing of all the names used for this module. 

 

(I think) Skoda/VW decided to simplify (and make more profitable) their aftersales of these units by supplying just the 'high end' 6Q0937049F to cover any replacement of lower-spec 6Q1 and 6Q2 varieties.

I have a spare 6Q1 unit I bought out of curiosity recently which I might attempt to fit to my Polo to test if it works and is OK. It's not supposed to be correct for the car, but apart from one row of connectors being in a physically different position, it seems very similar to the suffix C/D versions.

 

I'll try to look at this again in the next few days. There's probably a single connector you can remove temporarily from this unit to see if the drain reduces significantly. XP4 which has the main earth wire on pin 2 seems like a good candidate.  Doing this will potentially disrupt a lot of systems though, so don't lock the car with this connector out.  

 

What I suggest you try is to unplug this connector, leave driver's door open, then come back after half an hour to measure the mV across fuse 22.