Cabin heater & A/C stopped working

[robin_cox]

A week or so ago I found that I was no longer able to engage the volcanic cabin heater to keep my office temperature comfortable - given the recent return to colder conditions this was rather depressing. I also realised that the a/c light (that I previously left permanently active to keep condensation away) no longer activates, either by turning the temperature to full low, or by pressing the a/c button.

Finally had time to attach VCDS and have a look to see if there are any fault codes.

2 identified initially :

65542 - Control module not coded.
time and date triggered when van was started up a week ago on Friday.

524545 - AC compressor first run-in "Not performed"
time and date triggered exactly the same time as the above.

I'm wondering if there was a momentary low voltage during cranking that upset the ECU, but now I have no idea how to "recode" the module, or undertake an a/c run in procedure.

I tried a couple of output tests - temp flap motor output test being the first. Clicked "Start", and after a moment or so there was a response "refused by control module, 7F2F24". It did this with every other test in the list that I tried.

I looked at some advanced measurement values. The refrigerant pressure is 4bar or higher when the vehicle is started, so it's not that the system had lost gas. The various temperature / air direction control knobs show expected readout values when you rotate them, and the a/c button is detected as being pressed when you press it.

I did then manage to run a temperature flap motor output test, and it was cycling from one extreme to the other both in requested value and actual position, although the van hadn't had time to warm up enough to really see if hot air was coming out. I also then managed to run an a/c compressor output test, and the a/c light flashed on and off repeatedly so something is happening but I'm not sure what.

I've read several threads here and am aware that the temperature flap actuator arm is a known weak point that may need replacing (will check).

Once I'd been messing around for a while I checked for fault codes again (having cleared them), and there were now 4 - control module not coded, ac compressor first run-in not performed, 9475857 Position sensor for temp flap motor intermittent short to ground, and 9473906 Motor for temp flap missing calibration / basic setting.

The question I have for people who know what they're doing is : how would I resolve the two original fault codes detected in VCDS - namely coding of the control module, and the a/c compressor run-in procedure?

many thanks, Robin

 

[robin_cox]

Edited to add :

I've solved the a/c compressor run-in fault message.

Followed the instructions applicable for the 5th/6th generation Golf on the Rosstech wiki -

VW Golf (5K) Climatronic - Ross-Tech Wiki

Everything plugged in, engine started. Basic settings for the flaps end-stops run, followed by having to 'adapt' the duration of basic settings for compressor run-in from 120 seconds to 120 seconds as it threw an error on the first basic settings attempt. Then ran basic settings, compressor run-in automatic, which took around 2 minutes with the a/c light flashing, and after this was completed, full a/c activability has been restored.

I have not yet resolved the module coding fault code, nor the temperature issue - but then again I've not run the van long enough to get hot air.

 

[mmi]

Please share full VCDS Auto-Scan - would be helpful to know what's the vehicle in question.

 

[robin_cox]

It will take a little while - I am only free on Sundays, and the computer that I use for the VCDS isn't connected to the web so the scan will involve mucking about with USB sticks.

 

[lee_m]

Im having the same problem with a mates van
I can not get the a/c compressor break-in fault code B109EF0, i try and reset it but it just times out and wont do the test..
If I manually activate the A/c compressor then the A/c works
Im using Obd eleven

 

[robin_cox]

Im having the same problem with a mates van
I can not get the a/c compressor break-in fault code B109EF0, i try and reset it but it just times out and wont do the test..
If I manually activate the A/c compressor then the A/c works
Im using Obd eleven

View attachment 319982

Did you do the flap end-stops 'basic settings' before the compressor run-in protocol? Mine wouldn't reset the compressor run-in until the end-stops procedure had been done as well as following Rosstech's advice on the adaption value for the compressor run-in duration.

I have working a/c but no control over the heat at the moment - after days of barely enough heat I've been gently poached the last couple of days!

 

[robin_cox]

Please share full VCDS Auto-Scan - would be helpful to know what's the vehicle in question.

Herewith.

Couple of things I've noted lower down - fault codes in things like the distance control and telematics caused by low voltage on 9th March - that was when it was being restarted after a fuel line connector pinged off and I had to get recovered back to my mechanics for them to resolve it. Have cleared those already.

New headlamp switch is on order after a second-hand one (cheap) had the same problem as the original.

Couple of other errors all happened within 2-3 seconds on 26th Feb (no idea of what the event was).



Thursday,19,March,2026,18:25:11:25966
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x86
VCDS Version: 25.3.2.0 HEX-V2 CB: 0.4671.5
Data version: 20250822 DS365.0
www.Ross-Tech.com


VIN: WV1ZZZ7HZLH...... License Plate:


Chassis Type: 7H-VN46 (3Q0)
Scan: 01 03 08 09 10 13 15 17 19 22 44 5F 75

VIN: WV1ZZZ7HZLH...... Mileage: 193051km-119956miles

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: OK 0000
13-Auto Dist. Reg -- Status: Malfunction 0010
15-Airbags -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: Malfunction 0010
22-AWD -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
5F-Information Electr. -- Status: Malfunction 0010
75-Telematics -- Status: Malfunction 0010
-------------------------------------------------------------------------------
Address 01: Engine (J623-CXHA) Labels:. 04L-907-309-V2.clb
Part No SW: 04L 906 056 RT HW: 04L 907 445 M
Component: R4 2.0l TDI H01 9972
Revision: 23301001
Coding: 001940144326050900000000000000000000000000000000
Shop #: WSC 00012 790 00073
ASAM Dataset: EV_ECM20TDI03004L906056RT 005006
ROD: EV_ECM20TDI03004L906056LE_005.rod
VCID: 107E6CCA2AE5256A1E3-8044
VINID: 9E606AAAA1D8A9C6000C30841C241A35E8

No fault code found.
Readiness: N/A

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104) Labels: 7LX-614-517-V1.clb
Part No SW: 7LB 614 517 A HW: 7LB 614 517
Component: ESC_base H01 0700
Serial number: 08509551191025
Coding: 30554452484AEE880C5622A8126D7706392120B8
Shop #: WSC 00012 790 00073
ASAM Dataset: EV_Brake1ESP90iBOSCHVN46X 002010
ROD: EV_Brake1ESP90iBOSCHVN46X_002.rod
VCID: 3E22E27240F1E31ABCF-806A

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J301) Labels:* Redir Fail!
Part No SW: 7LA 907 426 B HW: 7LA 907 426 B
Component: AC Manuell H01 0502
Coding: 012000000800010001100400004401050000000000000000000000000000
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_AirCondiBHTCT6PA 001004
ROD: EV_AirCondiBHTCT6PA.rod
VCID: 42DA9682340987FAD87-8016

Rear air conditioning block 1:

2 Faults Found:
65542 - Control module not coded
U1013 00 [00001001] - -
[Steuerger‰t nicht codiert - keine Anzeige]
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 23
Mileage: 192374 km
Date: 2026.03.15
Time: 14:46:46

9473906 - Motor for Temperature Flap
B108F 54 [00001001] - Missing Calibration / Basic Setting
[Stellmotor f¸r Temperaturklappe - keine Grundeinstellung]
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Reset counter: 23
Mileage: 192374 km
Date: 2026.03.15
Time: 14:46:47


-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519) Labels: 2QX-937-BCM-V1.clb
Part No SW: 2Q5 937 090 HW: 2Q5 937 090
Component: BCM T6PA Std+ H10 0935
Serial number: 01101935201294 Dataset Number: V03935315CB 0001
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_BCMA0 205001
ROD: EV_BCMA0_205_VW27.rod
VCID: 74B6005A3E3D794A9AB-8020

Driver door control module:
Subsystem 1 - Part No SW: 7L1 959 405 HW: 7L1 959 163
Component: FHSG_DRV 001 0002
Serial number: 00000000000032224866
Coding: 1F0008

Front passenger door control module:
Subsystem 2 - Part No SW: 7L1 959 406 HW: 7L1 959 164
Component: FHSG_PSG 001 0002
Serial number: 00000000000035280602
Coding: 050000

Anti-theft alarm system sensor:
Subsystem 3 - Part No SW: 5Q0 951 172 HW: 5Q0 951 172
Component: Sensor, DWA 005 0316
Serial number: 000000000ZY193253V56

Alarm horn:
Subsystem 4 - Part No SW: 5Q0 951 605 A HW: 5Q0 951 605 A
Component: Sirene, DWA 005 0314
Serial number: 00000000000047940879

1 Fault Found:
919560 - Light Switch
B126A 29 [00001001] - Signal Implausible
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 4
Fault Frequency: 1
Reset counter: 23
Mileage: 192374 km
Date: 2026.03.15
Time: 12:59:30

Zusaetzliche Umgebungsdaten-Terminal 15 status: On
Zusaetzliche Umgebungsdaten-Terminal 50 status: OFF
Zusaetzliche Umgebungsdaten-Low beam: Not operated
Zusaetzliche Umgebungsdaten-OFF: Not operated
Zusaetzliche Umgebungsdaten-Outside temperature: -50.0 ∞C
Zusaetzliche Umgebungsdaten-Automatic high beam assist: Not operated
Zusaetzliche Umgebungsdaten-Position lamps: Not operated
Zusaetzliche Umgebungsdaten-Parking light left: Not operated
Zusaetzliche Umgebungsdaten-Parking light right: Not operated
Zusaetzliche Umgebungsdaten-CAN-Bus_aktiv: On
Zusaetzliche Umgebungsdaten-last wakeup: keine Stoerschutzursache
Zusaetzliche Umgebungsdaten-Status Bremslichtschalter (CAN): OFF
Zusaetzliche Umgebungsdaten-Status Bremslichtschalter (HW): OFF
Zusaetzliche Umgebungsdaten-voltage measurement: 12.4 V


-------------------------------------------------------------------------------
Address 10: Park/Steer Assist (J446) Labels:| 5Q0-919-283.clb
Part No SW: 5QA 919 283 E HW: 5QA 919 283
Component: PDC 4 Kanal H08 0061
Serial number: 000150059319338 Dataset Number: V03935304BN 0001
Coding: 0601050001
Shop #: WSC 12345 123 12345
ASAM Dataset: EV_EPHVA14AU3700000 009044
ROD: EV_EPHVA14AU3700000_009_SK25.rod
VCID: 4CC6B8BA064D418A22B-8018

No fault code found.

-------------------------------------------------------------------------------
Address 13: Auto Dist. Reg (J428) Labels:| 2Q0-907-572.clb
Part No SW: 2Q0 907 572 R HW: 2Q0 907 572 B
Component: ACCCONTIMQB H03 0372
Dataset Number: V03935303EM 0001
Coding: 2A00600201FF8748949C815500508700000000000000000004
Shop #: WSC 12345 123 12345
ASAM Dataset: EV_ACCMRRCONTIVW376 003016
ROD: EV_ACCMRRCONTIVW376_VW41.rod
VCID: 43D493862B138EF2D31-8016

1 Fault Found:
1389 - Function Restricted due to Insufficient Voltage
U1400 00 [00001000] - -
[FAULT_VBAT_BUSMON_LOW]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 51
Mileage: 191304 km
Date: 2026.03.09
Time: 11:38:15

Voltage terminal 15: 9.7 V
Control Module temperature: 11 ∞C
Vehicle speed: 0.00 m/s
Longitudinal acceleration: 0.19 m/s≤
Adaptive distance regulation: status: ACC_reversible_error


-------------------------------------------------------------------------------
Address 15: Airbags (J234) Labels:| 2Q0-959-655.clb
Part No SW: 2Q0 959 655 AD HW: 2Q0 959 655 AD
Component: VW22Airbag 015 0506
Revision: -------- Dataset Number: V03935308TZ 0001
Coding: 8800C00000000000400000CF008C40000065
Shop #: WSC 00012 790 00073
ASAM Dataset: EV_AirbaVW22BPAVW27X 001022
ROD: EV_AirbaVW22BPAVW27X.rod
VCID: 7F5CDF76077B2A12F79-802A

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285) Labels:| 7LA-920-XXX-V1.clb-SRI3
Part No SW: 7LA 920 941 HW: 7LA 920 941
Component: KOMBI 204 6750
Coding: 27A412002080260001882A010401000000200000
Shop #: WSC 00012 790 00073
ASAM Dataset: EV_DashBoardVDDMQBAB 009069
ROD: EV_DashBoardVDDMQBAB_VN46.rod
VCID: 7DA0257E0D773802E55-8028

2 Faults Found:
16777018 - Function Restricted due to Interrupted Communications
U1110 00 [00001000] - -
[BAP_Audio_0x31 keine Kommunikation]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 34
Mileage: 190282 km
Date: 2026.02.26
Time: 15:40:40

16777020 - Function Restricted due to Interrupted Communications
U1110 00 [00001000] - -
[BAP_TEL_0x28 keine Kommunikation]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 34
Mileage: 190282 km
Date: 2026.02.26
Time: 15:40:39


-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533) Labels:| 3Q0-907-530-V1.clb
Part No SW: 3Q0 907 530 AC HW: 3Q0 907 530 C
Component: GW MQB High 521 5388
Serial number: 13121910803943 Dataset Number: V03935320AV 0001
Coding: 030100044F05730000000008000F00010001070000000000000000000000
Shop #: WSC 00012 790 00078
GVL: 01C43C0000000000400080008000480000000000000000000000000000000000
ASAM Dataset: EV_GatewNF 013026
ROD: EV_GatewNF_SK25.rod
VCID: 70BE0C4A4A25456A7E3-8024

Generator:
Component: 4-01-09-01-04

Multifunction steering wheel control module:
Subsystem 2 - Part No SW: 3G0 959 442 E HW: 3G0 959 442 E Labels: 3C8-959-537.CLB
Component: E221__MFL-PR6 H06 0110
Serial number: PR6-0440036328191506
Coding: 281C00

Battery Monitoring Control Module:
Subsystem 3 - Part No SW: 7E0 915 181 N HW: 7E0 915 181 N
Component: J367-BDMConti H03 1052
Serial number: 773433010019120900D9

2 Faults Found:
66052 - Infotainment CAN Bus (SAE Bus E)
U0065 00 [00001000] - Performance
[Globaler Timeout CAN-Infotainment]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Reset counter: 34
Mileage: 190282 km
Date: 2026.02.26
Time: 15:40:38

Terminal 30 power supply: 12.9 V
Terminal 15: On

8531970 - Quiescent Current
U1406 00 [00001000] - Too High
[Ruhestrom oberer Grenzwert ¸berschritten]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 7
Fault Frequency: 13
Reset counter: 65
Mileage: 187790 km
Date: 2026.01.22
Time: 20:32:36

Terminal 30 power supply: 12.4 V
Terminal 15: OFF


-------------------------------------------------------------------------------
Address 22: AWD (J492) Labels:| 0CQ-907-554-V1.clb
Part No SW: 0CQ 907 554 L HW: 0CQ 525 130 C
Component: Haldex4Motion H56 7822
Serial number: HA1-00017.09.19 Dataset Number: v1260x015G0 0000
Coding: 0001
Shop #: WSC 00012 790 00078
ASAM Dataset: EV_AllWheelContrHA1VW37X 004013
ROD: EV_AllWheelContrHA1VW37X_VN46.rod
VCID: 4EC2B2B2F051739A4CF-801A

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist (J500) Labels:| 2N0-909-143.clb
Part No SW: 7LA 909 144 F HW: 7LA 909 144 D
Component: EPS_MQB_ZFLS 751 7150
Dataset Number: V03935309JN 0001
Coding: 0106
Shop #: WSC 00012 790 00078
ASAM Dataset: EV_SteerAssisMNB 002012
ROD: EV_SteerAssisMNB.rod
VCID: 45D08D9E2527B0C2FD5-8010

No fault code found.

-------------------------------------------------------------------------------
Address 5F: Information Electr. (J794) Labels:| 5G0-035-MIB-ENT2.clb
Part No SW: 3G0 035 869 B HW: 3G0 035 869 B
Component: MU-E-D-ER 715 0740
Serial number: 22111900020321 Dataset Number: V03935316KK 0001
Coding: 066401003C00000041110101008000001F0000C60000010000
Shop #: WSC 00012 790 00073
ASAM Dataset: EV_MUEnt4CGen2LGE 001044
ROD: EV_MUEnt4CGen2LGE_VN46.rod
VCID: 2B04DB26A38366B20B1-807E

2 Faults Found:
7169 - Function Restricted due to Missing Message(s)
U1111 00 [00001001] - -
[A/C system (0x01) - function restriction due to communication error - BapErr_retry not successful]
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 9
Mileage: 191248 km
Date: 2026.03.06
Time: 08:26:49

Voltage terminal 30: 13.1 V
BAP-BAP_Function_ID: 00

7178 - Function Restricted due to Missing Message(s)
U1111 00 [00001001] - -
[Park assist OPS (0x0A) - function restriction due to communication error - BapErr_retry not successful]
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 1
Reset counter: 163
Mileage: 185031 km
Date: 2025.12.22
Time: 22:05:46

Voltage terminal 30: 12.0 V
BAP-BAP_Function_ID: 00


-------------------------------------------------------------------------------
Address 75: Telematics (J949) Labels:* Redir Fail!
Part No SW: 5WA 035 282 HW: 5WA 035 282
Component: OCUGen3Low H14 0083
Serial number: 0000000909NVWP4 Dataset Number: V03935314UT 0001
Coding: 06462000196818008005460160000607
ASAM Dataset: EV_OCUGen3Low 002036
ROD: EV_OCUGen3Low_002_VW27.rod
VCID: 0158598E718F5CE281D-8054

2 Faults Found:
7170 - Function Restricted due to Missing Message(s)
U1111 00 [00001000] - -
[Multi Function Display (0x0F) - Funktionseinschr‰nkung wegen Kommunikationfehler - BapErr_RetryNotSuccessful]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 6
Fault Frequency: 60
Reset counter: 39
Mileage: 185204 km
Date: 2026.01.04
Time: 11:17:15

Voltage terminal 30: 12.1 V

2566 - GPS Antenna
B1054 13 [00001000] - Open Circuit
[GPS-Antenna - Interruption]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 4
Fault Frequency: 1
Reset counter: 26
Mileage: 0 km
Date: 2000.00.00
Time: 00:00:00

Voltage terminal 30: 12.9 V


End----------(Elapsed Time: 01:20, VBatt start/end: 12.2V/12.2V)-----------
------------------------------12 Faults Found------------------------------