Polo 6R - Auto HVAC - compressor not running when starting in AUTO mode

Tomba · Jul 31, 2018

Dear members,

I have a 2010 Polo 1.2 TDI (75bhp) with a strange A/C error.
Once you start the car and the HVAC is in AUTO mode with A/C ON, the A/C starts up but disengages the compressor within a few seconds. VCDS Compressor Shut-Off code is then #16 = Compressor activation faulty.

In the error memory it is mentioned that the communication with the Engine ECU is lost for a while. Funny thing is,
Once you turn the AUTO mode OFF and A/C OFF and then start the car, wait a few seconds and put it back to AUTO mode with A/C ON. No issues are involved -> fine working A/C.

Code:

Tuesday,31,July,2018,12:41:56:20481
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 18.2.1.5 (x64)
Data version: 20180518 DS287.2
www.Ross-Tech.com


VIN: WVWZZZ6RZBY083303   License Plate: 90-NLD-2
Mileage: 258700km-160748mi   Repair Order: Johannes



--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Chassis Type: 6R-VW25 (6R0)
Scan: 01 03 08 09 15 17 19 25 44 56 61 69

VIN: WVWZZZ6RZBY083303   Mileage: 258700km-160748miles

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
15-Airbags -- Status: OK 0000
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
56-Radio -- Status: OK 0000
61-Battery Regul. -- Status: OK 0000
69-Trailer -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine (J000-CFWA)       Labels:. 03P-906-021-CFW.clb
   Part No SW: 03P 906 021 B    HW: 03P 906 021 B
   Component: R3 1.2l TDI   H04 9979  
   Revision: 12004001    Serial number:               
   Coding: 00114014032401080000
   Shop #: WSC 49310 002 1048576
   ASAM Dataset: EV_ECM12TDI03103P906021B 001042
   ROD: EV_ECM12TDI03103P906021AA.rod
   VCID: 275A7E2E5EBD157C45-8072

No fault code found.
Readiness: 0 0 0 0 1 

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 6R0-907-37x-ESP82.clb
   Part No SW: 6R0 907 379 AJ    HW: 6R0 907 379 AF
   Component: ESP8.2i front H05 0001  
   Revision: --------    
   Coding: 210224E3417500B5842824E282D400521300
   Shop #: WSC 00788 648 00255
   VCID: 060413AAB5772C741E-8052

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J255)       Labels: 6R0-907-044.clb
   Part No SW: 6R0 907 044 B    HW: 6R0 907 044 B
   Component: Climatronic   H08 0305  
   Revision: V0000000    
   VCID: 326C9F7A6D7F60D4E2-FFFE

4 Faults Found:
00457 - Control Module for Network (J519) 
            013 - Check DTC Memory - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 92
                    Mileage: 258021 km
                    Time Indication: 0
                    Date: 2012.12.16
                    Time: 12:50:47

00898 - Control Circuit A/C compressor 
            010 - Open or Short to Plus - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 92
                    Mileage: 258021 km
                    Time Indication: 0
                    Date: 2012.12.16
                    Time: 12:50:47

01314 - Engine Control Module 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 92
                    Mileage: 258021 km
                    Time Indication: 0
                    Date: 2012.12.16
                    Time: 12:50:47

00898 - Control Circuit A/C compressor 
            007 - Short to Ground - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 92
                    Mileage: 258021 km
                    Time Indication: 0
                    Date: 2012.12.16
                    Time: 12:50:47


-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 6R0-937-08x-09.clb
   Part No SW: 6R0 937 088 F    HW: 6R0 937 088 
   Component: BCM PQ25 Re4  H46 0355  
   Revision: BU046001    Serial number: 0328 224100354
   Coding: 22B02BBF08A10000202009B02E2B0CD05F80612F7E860441200000000000
   Shop #: WSC 23324 000 1048576
   VCID: 418EC0B6D8D9CB4C6B-8014

   Subsystem 1 - Part No SW: 6R0 959 801 R    HW: 6R0 959 801 R  Labels: 6R0-959-801.CLB
   Component: J386__TSG_FT  006 0903 
   Serial number: KU0-KU020.08.1012597
   Coding: 58BC30

   Subsystem 2 - Part No SW: 6R0 959 802 T    HW: 6R0 959 802 T  Labels: 6R0-959-802.CLB
   Component: J387__TSG_BT  006 0902 
   Serial number: KU0-KU018.08.1013212
   Coding: 48BC30

1 Fault Found:
03789 - Terminal 75 Limp Mode Active 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 93
                    Mileage: 258396 km
                    Time Indication: 0
                    Date: 2012.12.18
                    Time: 16:44:24


-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 5K0-959-655.clb
   Part No SW: 6R0 959 655 K    HW: 6R0 959 655 K
   Component: VW10Airbag00G H09 0020  
   Revision: --------    Serial number: 003GX00686UG
   Coding: 003047
   Shop #: WSC 00788 648 00255
   ASAM Dataset: EV_AirbaVW10BPAVW250 A01001
   ROD: EV_AirbaVW10BPAVW250.rod
   VCID: 4A9CE79AEDEF0814BA-801E

   Crash sensor for side airbag: driver side: 
   Serial number: 3572SRB40000C814C151

   Crash sensor for side airbag: front passenger side: 
   Serial number: 3582SRB40000C8D5010+

   Crash sensor for side airbag: rear: driver side: 
   Serial number: 3515RRB405H6THNCNH1I

   Crash sensor for side airbag: rear: passenger side: 
   Serial number: 3525RRB405H6THNC5GON

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5K0-920-xxx-17.clb-SRI1
   Part No SW: 6R0 920 861 F    HW: 6R0 920 861 F
   Component: KOMBI         H04 0304  
   Serial number: 00000000000000
   Coding: 140A00
   Shop #: WSC 00788 648 00255
   ASAM Dataset: EV_Kombi_UDS_VDD_RM09 A04086
   ROD: EV_Kombi_UDS_VDD_RM09_004_VW25.rod
   VCID: 3878AD5283038A84DC-806C

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels:. 6R0-907-530-V1.clb
   Part No SW: 6R0 907 530 B    HW: 1K0 907 951 
   Component: J533  Gateway   H28 0020  
   Revision:   H28       Serial number: 070710F2001758
   Coding: 7D0A1D00080000000002
   Shop #: WSC 46532 001 1048576
   VCID: 326C9F7AAD7F60D4E2-8066

No fault code found.

-------------------------------------------------------------------------------
Address 25: Immobilizer (J334)       Labels:| 5K0-920-xxx-25.clb
   Part No SW: 5K0 953 234     HW: 5K0 953 234 
   Component: IMMO          H04 0304  
   Serial number:               
   Coding: 000000
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03008
   ROD: EV_Immo_UDS_VDD_RM09.rod
   VCID: 6ADC471A8D2FE8149A-803E

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist        Labels: 6Q0-423-156.clb
   Part No: 6R0 423 156 B
   Component: LenkhilfeTRW        V277  
   Coding: 11230
   Shop #: WSC 00788  
   VCID: 2F6A960EEA4D4D3C8D-807A

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio (J503)       Labels:. 5M0-035-1xx-56.clb
   Part No SW: 5M0 035 186 J    HW: 5M0 035 186 J
   Component: Radio RCD310  042 0082  
   Revision: 01000001    Serial number: VWZ1Z2N1633380
   Coding: 01000400020001
   Shop #: WSC 00788 648 00255
   VCID: 33629A7E926569DCE9-8066

No fault code found.

-------------------------------------------------------------------------------
Address 61: Battery Regul. (J840)       Labels:. 1K0-907-534.clb
   Part No SW: 6R0 907 534     HW: 1K0 907 951 
   Component: Batt.regelung H28 0020  
   Serial number: 070710F2001758
   Coding: 030B1A5A
   Shop #: WSC 46532 001 1048576
   VCID: 74E05962D7EB2EE430-8020

   Component: J367-BDM  H07 0125 
   Serial number: 00000000002790000491

No fault code found.

-------------------------------------------------------------------------------
Address 69: Trailer (J345)       Labels:. 1K0-907-383-V2.clb
   Part No SW: 1K0 907 383 F    HW: 1K0 907 383 F
   Component: Towbar module H09 0100  
   Revision: 3A001001    Serial number: ÀÁ006789,-(00(
   Coding: 0100000100000000
   Shop #: WSC 00000 000 00000
   VCID: 30689572637352C494-8064

No fault code found.

End-------------------------(Elapsed Time: 02:05)--------------------------

Other modules like instrument cluster do not report similar error codes about engine control module communication so I doubt engine controller is faulty. I do get communication errors with VCDS while logging or checking parameters when reading the HVAC module.

A little history is,
Once the weather went hotter here the owner indicated that the A/C wasn't working properly. He went to the garage who mounted a new compressor which was faulty according to them. From this moment problems were detected by the owner. I don't know if the compressor is genuine or from a 3rd party supplier.
Car was chip-tuned after the summer and we are now checking if the tuning could be involved.
Next plan is,
flash back original S/W and check if symptoms stay away. If not flash back tuned software and troubleshoot further.

Maybe some of you have had such issue before.

Currently a 21W lamp is fitted in the interior to visually monitor the A/C clutch activity.

Other data from the HVAC:

Code:

Advanced Identification
     Identification: VD1-999
     Revision: V0000000
     Date: 29.08.10
     Manufacturer number: 0004
     Test stand number: 8579
Flash Status
     Programming Attempts(application): 0
     Successful Attempts(application): 0
     Programming Status: 00000000
     Flash Date: 0000.00.00
     Flash Tool Code: 39734 111 12345
Misc.
     Hardware number: 6R0 907 044 B
     Workshop System Name: J255
VCDS Info:
       VCID: 326C9F7A6D7F60D4E2-8066
       Labels: 6R0-907-044.clb

jyoung8607 · Jul 31, 2018

Excellent and detailed post, thank you.

Tomba said:
A little history is,
Once the weather went hotter here the owner indicated that the A/C wasn't working properly. He went to the garage who mounted a new compressor which was faulty according to them. From this moment problems were detected by the owner. I don't know if the compressor is genuine or from a 3rd party supplier.
Car was chip-tuned after the summer and we are now checking if the tuning could be involved.
Next plan is,
flash back original S/W and check if symptoms stay away. If not flash back tuned software and troubleshoot further.

Freeze-frames for compressor activation and ECU comms have the same freeze-frame data, down to the second, so they seem related. Compressor control is subject to data exchange with the ECM. Among other things, the HVAC controller informs the engine of compressor torque load so idle speed can be maintained more accurately, and it accepts shutoff requests from the ECM in case of the kickdown switch being activated (turning off the compressor under maximum acceleration commanded by the driver) or the engine overheating, etc. The HVAC controller may well refuse to keep the compressor engaged if it can't communicate with the ECU.

Your tune is certainly suspect here. The tuner may have copied code from another vehicle/platform using the same engine, but with different HVAC equipment. Or, the tuned ECU may have ended up with coding for manual HVAC without any controller, which might result in the ECU not sending/receiving the extra CAN messages needed for an auto HVAC controller. I don't have the coding table for your ECU so I can't confirm that; you might take a look on your end while connected with VCDS.

Your next step of returning to stock seems logical. The only thing that concerns me is your statement below:

Tomba said:
Other modules like instrument cluster do not report similar error codes about engine control module communication so I doubt engine controller is faulty. I do get communication errors with VCDS while logging or checking parameters when reading the HVAC module.

If you have problems getting VCDS to talk with the HVAC controller itself, there may be a problem with it, or its associated wiring...

Tomba said:
Currently a 21W lamp is fitted in the interior to visually monitor the A/C clutch activity.

... although it could be a self-induced brownout due to excessive load as a result of your diagnostic efforts. I'd verify that problem continues with wiring restored to stock.

Jack@European_Parts · Jul 31, 2018

What part number AC compressor/clutch is installed now and is it the correct part number?

FOD tuning indeed always a possibility, maybe someone messed with the RPM or cut out authorization map.

Did you check for stray voltages when in auto-mode from a back feed or current or ground and check all connectors shared for corrosion, including ECU since was tuned for FOD water ingress.

Tomba · Aug 2, 2018

Thanks for your replies gentleman, it is much appreciated.

I have checked my tuning data log before tuning and it mentions the same engine ECU coding as currently is being stored in the car. Yesterday we flashed back the original S/W and double checked the coding value. All values are equal before the tuning.

We have checked the A/C operation and after a period of shut down (car locked) the error still persists. Only the Engine ECU communication error codes is not present this time.

Code:

Thursday,02,August,2018,12:36:43:20481
VCDS Version: Release 18.2.1 (x64) Running on Windows 7 x64
www.Ross-Tech.com

                Address 08: Auto HVAC       Labels: 6R0-907-044.clb
Control Module Part Number: 6R0 907 044 B    HW: 6R0 907 044 B
  Component and/or Version: Climatronic   H08 0305
           Software Coding: 
            Work Shop Code:   
                      VCID: 326C9F7A6D7F60D4E1-8066
3 Faults Found:

00457 - Control Module for Network (J519) 
            013 - Check DTC Memory - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 99
                    Mileage: 258859 km
                    Time Indication: 0
                    Date: 2026.14.02
                    Time: 13:06:01

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: 61
                    Mileage: 258859 km
                    Time Indication: 0
                    Date: 2026.14.02
                    Time: 17:10:08

00898 - Control Circuit A/C compressor 
            007 - Short to Ground - Intermittent
             Freeze Frame:
                    Fault Status: 00100111
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 99
                    Mileage: 258859 km
                    Time Indication: 0
                    Date: 2026.14.02
                    Time: 17:11:50

Strange thing is,
The General control module communication is reported at 13:06 (when the car was shut down) and A/C compressor activation codes were triggered when the car was started again.

All other modules are error free

The owner did mention the following,

Once he starts the car in AUTO mode ON and A/C ON the first time the A/C compressor would activate shortly as described in my initial post. When he turns the engine OFF, ignition key removed for lets say 5 seconds and restarts the car. All is normal again -> the AUTO mode remains ON, A/C indications remains ON and the A/C compressor is activated. But only after the engine has been started shortly before.

For me it is strange that the A/C compressor activation codes have a Fault frequency of 1 while there were at least 2 events were the A/C was turned off.

We also observed that once we are deleting the error code memory while in AUTO mode ON, A/C ON and engine ON the ECU activates the clutch back on.

I completely agree with [jyoung8607] to make the wiring back to original and remove the 21W bulb. This is something for the garage that installed it in the first place.

At [Jack@European_Parts] the ECU was never removed for tuning, all is done by OBD.
The compressor part number is unknown to me. I will ask if receipts are available to review the part number.

I am completely with all of you to inspect the wiring for corrosion or other types of wrong connection behavior (bend male contacts or deformed female contacts).

I do would like to check the wiring diagram to verify how the A/C compressor clutch is activated and if there is a control valve on the A/C compressor. I will observe the voltages and current to [Jack@European_Parts] recommendation. Does some of you have wiring diagrams? Otherwise I would download them from the Techincal assistance site.

Thanks!

iichel · Aug 2, 2018

I think the coding of the engine should be 001140160324010800
byte 3 bit 1 + 2 == 1 --> Climatronic

EDIT: 36 --> 16.

Tomba · Aug 2, 2018

iichel said:
I think the coding of the engine should be 001140360324010800
byte 3 bit 1 + 2 == 1 --> Climatronic

Long coding helper sets,

?? = NO or Manual A/C (sorry don't remember anymore)
14 = Semi Automatic (current situation)
16 = Full automatic

iichel · Aug 2, 2018

6R0 907 044x = climatronic = full automatic, or am I seriously mistaken here?

00114016033401080000

14 -> 16 for climatronic
24 -> 34 for trailer

Tomba · Sep 3, 2018

Just spoke to the owner. The garage replaced the HVAC control unit / display for a second hand one and the problem is no longer present. :thumbs:

Polo 6R - Auto HVAC - compressor not running when starting in AUTO mode

Tomba

Verified VCDS User

jyoung8607

FoRT

Jack@European_Parts

Gone But Not Forgotten

Tomba

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iichel

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Tomba

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iichel

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Tomba

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