Fabia II Facelift Aircon issues / Headache

[RubenD]

Hi all,

 

I just introduced myself, also because I really need your help.

 

I february this year I bought a Fabia Combi 1.2TDI MY11. Besides the known EGR issue all was well except the aircon. It worked intermittently. Sometimes it worked for longer periods and than stopped. Switch engine off, wait a little), start -> AC working again. Until just before my summer leave (good thing we used our other car for the summer holiday).

 

I have been reading on the forum and have checked a lot already, unfortunatly to no avail. I think what to do next, but I might be overlooking something.

 

The car:

Fabia Combi 1.2TDI Facelift 2010 -> best build date I'm able to find is the first registration date -> 22-10-2010

VIN: TMBJK25J4B3091***
Chassis Type: 5J-SK25 (6R0)

Climatronic unit 5J0 907 044 B -> unit has a built date: 28-11-2014 -> which means it has been replaced before.

 

 

Errors in 08 HVAC:

Wednesday,31,August,2022,21:21:27:00009
VCDS Version: Release 21.9.0 Running on Windows 10 x64
www.Ross-Tech.com

                Address 08: Auto HVAC       Labels: 6Q0-907-044.lbl
Control Module Part Number: 5J0 907 044 B    HW: 5J0 907 044 B
  Component and/or Version: Climatronic   H09 0102
           Software Coding: 
            Work Shop Code:   
                      VCID: 295948A340F92BC136-807C
3 Faults Found:

00705 - Relay for Coolant Fan; Stage 1 (J279) 
            009 - Open or Short to Ground
             Freeze Frame:
                    Fault Status: 01101001
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 207
                    Mileage: 156320 km
                    Time Indication: 0
                    Date: 2063.14.31
                    Time: 21:04:47

00706 - Relay for Coolant Fan; Stage 2 (J513) 
            009 - Open or Short to Ground
             Freeze Frame:
                    Fault Status: 01101001
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 207
                    Mileage: 156320 km
                    Time Indication: 0
                    Date: 2063.14.31
                    Time: 21:04:47

00898 - Control Circuit A/C compressor 
            010 - Open or Short to Plus
             Freeze Frame:
                    Fault Status: 01101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 207
                    Mileage: 156320 km
                    Time Indication: 0
                    Date: 2063.14.31
                    Time: 21:17:13

 

I read various topics:

https://www.briskoda.net/forums/topic/205880-air-con-problem/

https://www.briskoda.net/forums/topic/419404-aircon-issue/

https://www.briskoda.net/forums/topic/380764-00705-relay-for-coolant-fan-stage-1-j279-31-00-open-or-short-to-ground/

 

What have I checked / noticed thus far (not necessarily in chronological order):

- Wiring from compressor control valve to climatronic-unit -> no damage

- Wiring from cooling fan to ECU/Fusebox -> no damage -> car also does not have the separate controlunit with 2 relais nor does it have a temperature sender in the radiator -> it has the newer version fan with 4p-connector and integrated PCB in motor (from factory). The fact that the controlunit isn't installed, to me, also explains errors 00706 & 00706. This also leads me to believe the car needs a C version climatronic unit?

- Tested fan via Output test, works perfectly fine.

- Pressure sensor works perfectly fine.

- Replaced the 4 AC fuses.

- The climatronic does not seem to have Software Coding, the field above is empty -> does this imply that the unit is toast? I do think so, I checked my other car and it is showing software coding.

- Bought a secondhand climatronic "B", also does not work, software coding is also empty -> I think it is toast as well.

- We replaced N280 (compressor control valve), probably a waste of time and money, maybe not. I'm not able to start the compressor run-in because the option is missing/unavailable, only "Flap Motors" is available.

- I monitored the shut-off codes, when the errors are cleared, AC off, engine off = 6.

  Engine started, AC off, blower off, 9.

  Activated AC, 0 and immediately jumped to 16 -> I think this is also because the climatronic is toasted and/or "run in" isn't completed.

  I'm not able to read the amps (value it not available in  Adv. Meas. Values) so I can't monitor the 0.800 limit in relation to the temps.

- Adaptations is also empty, only channel 00 is available, reset to factory defaults.

 

 

0 = Compr. ON

6 = Compr. OFF: ECON Mode active

9 = Compr. OFF: Blower OFF

16 = Compr. OFF: Compressor Activation faulty

 

Climatronic unit

Currently installed: 5J0 907 044 B

I think the car needs a 5J0 907 044 C instead of the B.

 

ETKA stated that the C version is for cars 08-11-2010 onwards.

Elsa shows wiring etc. changed as of May 2010 -> earlier in the year. My car matches these schematics (without relais J279 & J513).

 

 

Questions:

- Is there something else I can check or do?

- Can I "inject" software coding into the B unit? I do not know what the security key is, I was hoping this would unlock the unit to get it going again.

- Shell I try my luck with a secondhand 5J0 907 044 C climatronic unit?
  In the Netherlands we have this amazing company called AC Tronics, they can test and if need be repair the current unit, but I do believe that is a waste of money.

 

Any thoughts, please share these with me.

 

 

 

 

If somebody would like to get more data / input, please let me know!

[varooom]

Hiya,

 

Address 08: Auto HVAC (J255) Labels: 6Q0-907-044.lbl
Part No SW: 5J0 907 044 C HW: 5J0 907 044 C
Component: Climatronic H08 0103
Revision: K0000000
VCID: 2A5B592445698E1FD9-807E

 

 

Ain't no coding for B or C

[RubenD]

Thanks, how did you look that up?

[varooom]

Just now, RubenD said:

Thanks, how did you look that up?

Google, checked several VCDS scan logs.

[varooom]

Here you go Rueben,

 

You have it correct, the part should have been C not the B that was fitted

 

Just note it was dropped, so now C becomes 5J0 907 044 D

 

 

EDIT: Your build date will be very important, otherwise the correct part is 5J0 907 044 B!!!

Sorry if the above became a red herring.

Edited 31 August, 2022 by varooom
Additional Information

[RubenD]

Brain wave of this morning:

For error 00898 I checked the wiringloom. I measured resistence through the wiring. From connector to dashboard. No issues found.

 

Seen from the N280 valve backwards I think both wires could be unbroken but still could be stripped and thus make contact (signal to ground).

 

I think my best bet is to take apart the small bit of loom from compressor/altenator and check for cracks and creases in the skin of the 4 wires.

 

That still leaves 00705 & 00706 unresolved.

 

Thanks @varooom for the info. 22-10-2010 seems to be the first registration date. That implies an earlier build date. E.g. before 08-11-2010. The dealer can check the build date based on VIN?

 

I still do think my car is MY11 and therefore will work with the C or D. Although there could be a mismatch between climatronic and ECU?  

[varooom]

11 hours ago, RubenD said:

VIN: TMBJK25J4B3091***

The 10th character is year B in your VIN where this equals MY11, which I used for ETKA, however the build date is important which is why the part fitted should be correct.

 

Dealer should be able to decide exact build date, has to be after 08.11.2010 for the part to be as above.

 

 

If your car doesn't have the fan relay for doubled speed (AFAIK) then car coding might be incorrect, which is why it reads the faults.  It would have been there all the time, and unable to clear.

 

If you can clear those 2 fan relay faults... Odds are you do have that relay.

 

Just my own thoughts.

[RubenD]

100% sure my car does not have the relaybox on the left chassisleg. It has the PCB in the fanmotor.

 

As per attached plan (my car doesn’t have the second fan) is how my car is set up.

[varooom]

Could be a coding issue, or the ECU has seen something and spat out the error incorrectly.

Definitely a weird thing to have a fault code for something not physically fitted.

 

Does it actually clear in VCDS?

If yes, does it come back right away or after time?

 

Glad to see you have wiring diagrams, makes life easier.

[RubenD]

When I erase the errors they clear. But immediatly pop-up when the car is started.

[Breezy_Pete]

I wonder if there is a software version in  suffix B units that suit J279/J513 applications, and a different software version that suits the 'module in fan' version? And you have a suffix B HVAC module with the first of those software variants. 

The mis-match between dates of  wiring diagram changes and ETKA part number changes seems to suggest that this might be what's going on? Almost that it must?

 

If it was as simple as "suffix - C/D suits the module inside fan, suffix B suits separate fan control module" then the dates just can't be made to work.

Edited 1 September, 2022 by Breezy_Pete

[RubenD]

18 minutes ago, Breezy_Pete said:

If it was as simple as "suffix - C/D suits the module inside fan, suffix B suits separate fan control module" then the dates just can't be made to work.

I do think this is the case. But I’ll first disassemble the wiring loom. At the moment I do think a damaged wire is causing the 00898.

 

I guess I’ll buy a secondhand C or D unit, just to see what will happen. Schematics are (as mentioned above) for May 2010 onwards.

[varooom]

Not to rain on your parade, but the actual main ECU could be your culprit.

It keeps flagging up the fault codes for the relays, if they don't actually exist... then maybe it's lost the plot?

 

I also realise that dates stored in ECU for fault codes don't always align with real life of course.

Maybe VAG know something we don't and we are going to get 14 months in the future!

14 hours ago, RubenD said:

  Date: 2063.14.31

 

If the ECU detects a fault on the fan circuit (amongst other checks) then AC will be disabled.

Perhaps if you can PM your full VIN, then it can be decoded to know for sure build date and if you have the fan relay hidden away somewhere.

Certainly might clear that issue up.

 

Alternatively, keep stripping away at the loom to determine if you have a broken wire as the ECU thinks it has.

[Breezy_Pete]

1 hour ago, varooom said:

It keeps flagging up the fault codes for the relays

 

The way I read the scan in the OP, it's the HVAC module that's saying there's relay faults, not the engine ECU?

 

 

15 hours ago, RubenD said:

Tested fan via Output test, works perfectly fine.

 

From within module 08, or from within module 01?

 

 

Having just looked at ETKA pages for 2010/2011 there's nothing to indicate the existence of suffix -B modules with any 'choice' of software/firmware pre-programming. That suggests my idea about differently programmed modules with the same part number to suit different fan configurations is very doubtful, I think.

[varooom]

I hear you Pete, but I wonder if when the user presses AC button, it sends signals over the canbus to various parts of course, and also get's feedback from Engine ECU saying it cannot start due to the mysterious relay box issue (coding or a fault in ECU) being a lack of a actual fault (to be determined by VIN)

 

As it was the HVAC that made the request and was denied by ECU, then it stores fault in that location?

 

Need a computer degree on these cars sometimes!

For sure this is an interesting thread.

[Breezy_Pete]

In the implementation where there is a separate fan control module, the engine ECU doesn't have any (direct) dealings with it though. Inputs are either from radiator thermoswitch(es) or HVAC module. No data to it from anywhere.

 

The version the OP has, without fan control module, the converse is true, all control is direct from engine ECU on the blue/yellow wire, as I understand it. (PWM signal, I think, from memory)

 

It'll be nice to learn from this thread, assuming the problem does get resolved.  I have confidence that Ruben will triumph. 

 

[RubenD]

The posted 3 errors are from 08.

Only used 01 to test the fan.

 

Errors 00705 & 00706 are not related to the 00898 (my humble opinion). Please keep in mind, the aircon did work (intermittently).

 

So I’ll check the loom again. I hope this resolves 00898.

 

 

 

And considering “B” should be able to ask fan to operate, I think currently climatronic is not able to ask for forced/additional coolingfrom fan.

 

I therefore think I should try a C or D unit in order to resolve 00705 & 00706.
Im 100% sure I do not have the fan relay unit :). Loom is identical to schematics.

 

P.S. VW has 40 years to arrange the additional 2 months/year. I suppose we have to wait and see.

[Breezy_Pete]

10 minutes ago, RubenD said:

Errors 00705 & 00706 are not related to the 00898 (my humble opinion)

I agree.

 

12 minutes ago, RubenD said:

I therefore think I should try a C or D unit in order to resolve 00705 & 00706.

I agree, but maybe only after resolving the 00898, if a fault external to the HVAC module can be found for that.  The system may start behaving correctly despite showing those relay errors.

[varooom]

Sorry for the delays, here the plot seems to thicken a little.

 

 

Here is your build spec that will be useful to answer some questions about build date, now we know

TMBJK25J4B3091---.pdf

 

 

Here is the list of radiator fan parts that is decoded to your specific VIN

FAB 959-050 FI.pdf

According to the mothership, you should have the relay 😬

Well at least you did when you left the factory it would appear, unless they made a massive mistake.

 

Here is full list of part that could be fitted to cool the car down (just for complete picture)

FAB 959-050.pdf

 

 

Image of the critter

 

 

Not saying that you do have this, I know weird things could happen.

[Breezy_Pete]

How strange. 

[Breezy_Pete]

Is there a date code anywhere visible on the radiator fan that might indicate that it was/wasn't fitted during factory build?

 

 

[RubenD]

Thanks for all the input, I alreadt tried to get nearer to the fan, diffucult to get access to.

 

Lets see how the loom looks first

 

The loom looks as old as the car and standard as well. Really really strange.

[Breezy_Pete]

Could it be worth checking that the VIN is the same everywhere it's written/stamped on vehicle, documentation, in firmware within control modules?

[RubenD]

Well this evening wasn’t well spend. I took apart the loom from altenator to 8p connector. All is in good nick. So tomorrow I can wrap it up again. And put everything back together.

 

Brainwave:

I think I’m in a loop. ECU oversees proceedings and detect the new N280 valve. Blocks valve because compressor run in hasn’t been carried out.

 

But I’m unable to start this procedure (see screenshot) -> ECU keeps blocking the compressor. Blockage is now causing 00898 to pop up in 08.

 

So I think my best bet is: Put the loom back together. And to be 400% sure, check loom (2 wires from N280 connector) by measuring the resistance. Ground merges somewhere below the battery box.

 

Buy a C or D Climatronic unit and pray that it will be able to perform the compressor run in.

 

Any other suggestions?

 

 

VIN as shown in VCDS matches sticker in trunk.

[RubenD]

Or could it be something mechanical in the compressor after all. Pully incl. nut spins. Compressor never has made any stranges noises. Mechanic also didn’t noticed anything peculiar when he changed the valve.

 

So I would say it isn’t the compressor.

 

I think buying a C or D unit is the only option there is left, because I need to carry out the compressor run in.