Hello dear friends. I'm posting in hope of any help with the following. 

 

Suddenly my Skoda Octavia 2016 2.0 TDI 4x4 Scout with 300.000km on it started blowing cold air on the passenger side, no matter what temp it was set to. I tried the calibration trick in hopes of it just being a calibration issue, but 10-15 calibrations later, its still stuck. I've read out the following fault codes with VCDS:

 

329477 - Motor for Fresh Air / Recirculated Air Flap 
          B108B 54 [00001001] - Missing Calibration / Basic Setting

and 

329479 - Position Sensor for Fresh/Recirculated Flap Motor 
          B109B 15 [00001000] - Open or Short to Plus

 

I've tried reading about this, but what I've found indicates the whole flap assembly needs replacing and a lot of the dash has to come out to remove it? Do you have any suggestions for me to try?

 

Quote

Address 08: Auto HVAC (J255)       Labels:| 5G0-907-044.clb
   Part No SW: 5E0 907 044 M    HW: 5E0 907 044 M
   Component: Climatronic   H03 0907  
   Revision: 00001K06    
   Coding: 02010104004101011005000000101000
   Shop #: WSC 73430 031 00063
   ASAM Dataset: EV_ACClimaBHBVW37X 003017
   ROD: EV_ACClimaBHBVW37X_003_VW37.rod
   VCID: 2F3B1FEB3795E3D2FE9-807A

   Fresh air blower control module (front): 

   A/C pressure/coolant temperature sensor: 

   Air quality sensor: 

 

2 Faults Found:

329477 - Motor for Fresh Air / Recirculated Air Flap 
          B108B 54 [00001001] - Missing Calibration / Basic Setting
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 2
                    Fault Frequency: 2
                    Reset counter: 130
                    Mileage: 301355 km
                    Date: 2024.12.19
                    Time: 10:48:59

                    Voltage terminal 30: 14.1 V
                    Outside temperature: 2.0  C
                    Inside temperature: 21.1  C
                    Actual value for fresh air/recirculation air flow flap: 17
                    Actual value for fresh air/recirculation air flow flap: 0.0 %
                    Fresh air/recirculating air/back pressure door specified value: 92

 

329479 - Position Sensor for Fresh/Recirculated Flap Motor 
          B109B 15 [00001000] - Open or Short to Plus
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 2
                    Fault Frequency: 7
                    Reset counter: 176
                    Mileage: 301355 km
                    Date: 2024.12.19
                    Time: 10:49:04

                    Voltage terminal 30: 14.1 V
                    Outside temperature: 2.0  C
                    Inside temperature: 21.1  C
                    Actual value for fresh air/recirculation air flow flap: 17
                    Actual value for fresh air/recirculation air flow flap: 0.0 %
                    Fresh air/recirculating air/back pressure door specified value: 92

 

I was a little to late to edit the post, here's some additional info: 

I've also cycled all different settings a few times. Airflow seems normal in all wents, but cold on the passenger side. After clearing codes I started the car and tried calibration again, codes went away after a DTC clear, but it still blows noticable cold on passenger side.. I swapped a faulty blower motor 6 months ago, if that's relevant in any way.

 

Read codes again after running it for a while, and they came back.

Quote

Saturday,28,December,2024,22:21:15:35578
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 x64
VCDS Version: 24.5.0.0 (x64)  HEX-V2 CB: 0.4643.4
Data version: 20240429 DS355.0
www.Ross-Tech.com

Workshop Code: 210 01369 040505

VIN: TMBLK9NE4F0159659   License Plate: 

                Address 08: Auto HVAC       Labels: 5G0-907-044.clb
Control Module Part Number: 5E0 907 044 M    HW: 5E0 907 044 M
  Component and/or Version: Climatronic   H03 0907
           Software Coding: 02010104004101011005000000101000
            Work Shop Code: WSC 73430 031 00063
              ASAM Dataset: EV_ACClimaBHBVW37X 003017 (SK37)
                       ROD: EV_ACClimaBHBVW37X_003_VW37.rod
                      VCID: 2F3B1FEB3795E3D2FE9-807A

2 Faults Found:

329477 - Motor for Fresh Air / Recirculated Air Flap 
          B108B 54 [00001001] - Missing Calibration / Basic Setting
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 138
                    Mileage: 301838 km
                    Date: 2024.12.28
                    Time: 21:46:52

                    Voltage terminal 30: 11.1 V
                    Outside temperature: 9.5  C
                    Inside temperature: 13.5  C
                    Actual value for fresh air/recirculation air flow flap: 79
                    Actual value for fresh air/recirculation air flow flap: 32.5 %
                    Fresh air/recirculating air/back pressure door specified value: 78

 

329479 - Position Sensor for Fresh/Recirculated Flap Motor 
          B109B 15 [00001000] - Open or Short to Plus
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 2
                    Fault Frequency: 2
                    Reset counter: 178
                    Mileage: 301838 km
                    Date: 2024.12.28
                    Time: 22:09:56

                    Voltage terminal 30: 13.9 V
                    Outside temperature: 9.5  C
                    Inside temperature: 13.3  C
                    Actual value for fresh air/recirculation air flow flap: 28
                    Actual value for fresh air/recirculation air flow flap: 4.0 %
                    Fresh air/recirculating air/back pressure door specified value: 78

 

Edited 28 December, 20241 yr by Steinrawr

Short update, will try to get a better look at the car this weekend. I sometimes get hot air on the passenger side too, but it seems random. It has happened two times the last week, car is in use daily.

I think one side heat problems are commonly caused by heater matrix problems. Especially if it is right hand side what is cold (Driver or passenger side, depending where you live). Search this forum, there is many posts about it.

 

Driver side cold

Silica bag

Heater matrix

Edited 4 January, 20251 yr by RattleWagon

26 minutes ago, RattleWagon said:

I think one side heat problems are commonly caused by heater matrix problems. Especially if it is right hand side what is cold (Driver or passenger side, depending where you live). Search this forum, there is many posts about it.

 

Driver side cold

Silica bag

Heater matrix

 

My only reason for nut suspecting that, is the fault codes on the flaps. My reasoning was "if the heater matrix or silica is bad, then the flaps wouldn't give a fault code". But i am only guessing. 

The flap motor issue is a different problem and they do sadly go bad.  It seems to be quite a common problem.  Quite seperate from the Silica teabag / bag of doom issue.

I see. 

 

It would just be Odd to me, that both has happened at the same time. Didn't get time to look at the car this weekend after all, so will have to wait to see what I can do. 

So. 

 

Did a lot of testing today, and i cant see any flaps not moving correctly. When using vcds to test the Recirculated Air Flap it moves without issues, and test values indicates it functions just as the left flaps. All values are identical left and right when using vcds to measure.  But... Dtcs just come back. 

 

I tried checking the silica bag, but i have the closed chamber type of reservoar, so cant just take it out or inspect it before i get the reservoar replacement. 

So.. The silica bag was intact, and my coolant was not at all cloudy or indicating any contaminants. I removed it from my reservoar, and replaced the reservoar with one without the bag. 

 

Im starting to doubt it's the heater matrix, but at the same time I dont understand why i have the problems since I can see all parts move under the dash. 

 

Will a faulty temp sensor be able to force down the temp on the passenger side? 

Well yes I guess there cud be faulty temp sensor in the cabin on passenger side that would drive the flaps so that no hot air is sent to passenger side when on automatic temp control. If you put it on manual and full blast high heat you shud get hot air from passenger side regardless of any temp sensors.

 

More likely it is the heater matrix.

7 minutes ago, RattleWagon said:

Well yes I guess there cud be faulty temp sensor in the cabin on passenger side that would drive the flaps so that no hot air is sent to passenger side when on automatic temp control. If you put it on manual and full blast high heat you shud get hot air from passenger side regardless of any temp sensors.

 

More likely it is the heater matrix.

 

Yeah, thanks. I just tried manually adjusting all flaps on full fan speed, with not even slightly warmer air at all on the passenger side. Also Just spoke to a friend with similar symptoms. His golf had a blocked matrix, I just ordered a new one myself, just hoping it will fit.

So, the end of it was that the matrix failed. It was clogged from about halfway across. 

 

Took a little hour to swap it. Plenty of space with the knee airbag removed and fairly easy actually. O-rings and clamps looked very good, so i kept them. Tip to anyone finding this, is to remove the coolant hose behind the right front wheel to practically remove everything in the system before disasmbling.