BCM coding for rear heated screen

[HoopDub]

I have a problem. I retro fitted a tailgate with heated rear window to an originally no window barn door van a few months ago. Ran all the extra wires i required to the BCM for the locking and rear screen heating to work. Coded the BCM and all was good. So i thought.
The past two mornings have been very frosty here and I've pressed the rear screen heater button, it illuminates, but the screen stays frosty.

I've checked voltage at the screen nearside uk passenger side is the positive and offside is negative. All i am getting is 5.7 volts, that being the BCM monitoring supply even with the switch turned to on (while van running).

Quick check of the BCM faults and a it showed was rear screen open circuit, where i had disconnected it to test the voltage. Cleared that and its back to no faults shown.

Output tests on the switch seem to work. Also i can hear the relay click in when i do an output test on the rear screen heater.

I am thinking it must be a coding problem, but i can't see the problem. I will add the scan log asap. I also checked the 08 hvac controller hoping it may be in there but no joy.

I searched the site, found one similar problem, but that thread was unresolved and a few years old now.

Any help appreciated.

 

[HoopDub]

Tuesday,04,March,2025,10:30:38:24488
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 x64
VCDS Version: 25.3.0.2 (x64) HEX-V2 CB: 0.4660.4
Data version: 20250228 DS364.1
www.Ross-Tech.com


VIN: WV1ZZZ7HZJH134300 License Plate: GF18UZM
Mileage: 253120km-157281mi Repair Order:



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


Chassis Type: 7H-VN75 (7E0)
Scan: 01 03 04 08 09 10 13 15 17 19 25 56 61 0B

VIN: WV1ZZZ7HZJH134300 Mileage: 253120km-157281miles

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: OK 0000
13-Auto Dist. Reg -- Status: OK 0000
15-Airbags -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: Malfunction 0010
25-Immobilizer -- Status: OK 0000
56-Radio -- Status: Sporadic communication error 1000
61-Battery Regul. -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (2D2D2-CXGA) Labels:. 04L-907-309-V2.clb
Part No SW: 04L 906 056 JS HW: 04L 907 445
Component: R4 2.0l TDI H02 4044
Revision: 23002001
Coding: 00114014430401090000
Shop #: WSC 02762 790 50316
ASAM Dataset: EV_ECM20TDI03004L906056JS 004004
ROD: EV_ECM20TDI03004L906056JS_004.rod
VCID: 074B97751FA8CEB2CEB-8052
VINID: 9E606AAAA1D8A9A6010C40C000460D17F7

No fault code found.
Readiness: N/A

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104) Labels: 7E0-907-37x-MK100ESC.clb
Part No SW: 7E0 907 379 P HW: 7E0 907 379 M
Component: ESC H06 0133
Revision: 00000000 Serial number: 60438000000740
Coding: 517E4098256584828A780276A48221E679F100
Shop #: WSC 02762 790 50316
ASAM Dataset: EV_Brake1ESCCONTIVN75XGP2 011001
ROD: EV_Brake1ESCCONTIVN75XGP2_011.rod
VCID: 3FDB4F9507F84672B6B-806A

No fault code found.

-------------------------------------------------------------------------------
Address 04: Steering Angle (G085) Labels:* 6R0-959-654.clb
Part No SW: 6R0 959 654 HW: 6R0 959 654
Component: LENKW.SENSOR H07 0070
Serial number: 29011813470065
Coding: 01
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_LWSKLOVW25X 005001
ROD: EV_LWSKLOVW25X.rod
VCID: 7EA5F29140728F7AFDD-802A

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J301) Labels:| 7E5-907-047.clb
Part No SW: 7E0 907 047 AK HW: 7E0 907 047 AK
Component: Climatic-T5 H22 0708
Revision: 00001002
Coding: 0000000003
Shop #: WSC 02762 790 50316
ASAM Dataset: EV_ClimaticT5 A01003
ROD: EV_ClimaT5Basis_VN75.rod
VCID: 73B3D3A57B30D212823-8026

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519) Labels:. 7E0-937-BCM-V1.clb
Part No SW: 7E0 937 090 C HW: 7E0 937 090 C
Component: BCM PQ25 Max4 H82 0752
Revision: B9082001 Serial number: 4000 037180296
Coding: E0A439380A212011002809342C2B84DC0F0070FF60464D70330400BB0840
Shop #: WSC 02762 534 156453
VCID: 2B030BC5E300CAD20A3-807E

Subsystem 1 - Part No SW: 7E0 959 801 R HW: 7E0 959 801 R Labels: 7E0-959-80X-V2.CLB
Component: J386__TSG_FT 005 0653
Serial number: KU0KU007021880382056
Coding: 1400B1

Subsystem 2 - Part No SW: 7E0 959 802 Q HW: 7E0 959 802 Q Labels: 7E0-959-80X-V2.CLB
Component: J387__TSG_BT 004 0653
Serial number: KU0KU005021880361125
Coding: 0400A1

Subsystem 3 - Part No SW: 2H0 959 442 HW: 2H0 959 442 Labels: 3C8-959-537.CLB
Component: E221__MFL-DC1 H02 0103
Serial number: 39180000826340058201
Coding: A4FFFF

1 Fault Found:
00975 - Heated Rear Window (Z1)
012 - Electrical Fault in Circuit
Freeze Frame:
Fault Status: 01101100
Fault Priority: 3
Fault Frequency: 1
Reset counter: 169
Mileage: 253112 km
Time Indication: 0
Date: 2019.07.25.
Time: 16:51:44


-------------------------------------------------------------------------------
Address 10: Park/Steer Assist (J446) Labels:| 7E0-919-475.clb
Part No SW: 7E0 919 475 AA HW: 7N0 919 475
Component: PARKHILFE 8K H06 0212
Revision: -------- Serial number: 28231801701002
Coding: 00800D
Shop #: WSC 02762 790 50316
ASAM Dataset: EV_VW75XParkAssis8K 001012
ROD: EV_VW75XParkAssis8K_001_VN75.rod
VCID: 71BFD9AD012CE00270F-8024

No fault code found.

-------------------------------------------------------------------------------
Address 13: Auto Dist. Reg (J428) Labels:| 7N0-907-572.clb
Part No SW: 7N0 907 572 C HW: 7E0 907 572
Component: ACC Bosch PQx H03 0211
Serial number: 0702180442AE37 Dataset Number: 7E0114v____ 0009
Coding: 00004000FE1779
Shop #: WSC 01383 790 50316
ASAM Dataset: EV_ACCBEGVW361 001006
ROD: EV_ACCBEGVW361.rod
VCID: 36352AB128C2873A65D-8062

6 Faults Found:
1380 - Internal Fault
B200F F0 [00001000] - -
[FAULT_ADC_VZ_BELOW_RADAR_OPERATION_LIMIT]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Reset counter: 184
Mileage: 252421 km
Date: 2025.02.14.
Time: 08:16:59

Control Module temperature: 9 C
Voltage terminal 15: 6.9 V
Vehicle speed: 0.07 m/s
Acceleration: -0.32 m/s

1130 - Sensor for Automatic Distance Control
C110B F0 [00001000] - Limited Visibility
[FAULT_SENSOR_NO_FREE_SIGHT]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 9
Fault Frequency: 2
Reset counter: 194

Control Module temperature: 9 C
Voltage terminal 15: 11.5 V
Vehicle speed: 0.00 m/s
Acceleration: 0.00 m/s

1132 - Sensor for Automatic Distance Control
C110B F0 [00001000] - Limited Visibility
[FAULT_SYSTEM_DISTURBED]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 9
Fault Frequency: 5
Reset counter: 194
Mileage: 251135 km
Date: 2024.12.25.
Time: 21:18:18

Control Module temperature: 20 C
Voltage terminal 15: 14.5 V
Vehicle speed: 5.19 m/s
Acceleration: -1.27 m/s

1131 - Sensor for Automatic Distance Control
C110B F0 [00001000] - Limited Visibility
[FAULT_SYSTEM_NO_FREE_SIGHT]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 9
Fault Frequency: 2
Reset counter: 194

Control Module temperature: 9 C
Voltage terminal 15: 11.5 V
Vehicle speed: 0.00 m/s
Acceleration: 0.00 m/s

1542 - Sensor for Automatic Distance Control
C110B F0 [00001000] - Limited Visibility
[FAULT_SENSOR_BLIND]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 4
Fault Frequency: 5
Reset counter: 194
Mileage: 251135 km
Date: 2024.12.25.
Time: 21:18:18

Control Module temperature: 20 C
Voltage terminal 15: 14.5 V
Vehicle speed: 5.19 m/s
Acceleration: -1.27 m/s

1545 - Sensor for Automatic Distance Control
C110B F0 [00001000] - Limited Visibility
[FAULT_SYSTEM_BLIND]
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 4
Fault Frequency: 5
Reset counter: 194
Mileage: 251135 km
Date: 2024.12.25.
Time: 21:18:18

Control Module temperature: 20 C
Voltage terminal 15: 14.5 V
Vehicle speed: 5.19 m/s
Acceleration: -1.27 m/s


-------------------------------------------------------------------------------
Address 15: Airbags (J234) Labels:| 5K0-959-655.clb
Part No SW: 7E0 959 655 J HW: 7E0 959 655 J
Component: VW10Airbag021 010 0018
Revision: -------- Serial number: 003EK000C4DN Dataset Number: 7E0003V____ 0905
Coding: 000000000000000000000000000000003231
Shop #: WSC 02164 790 50316
ASAM Dataset: EV_AirbaVW10BPAVW12X 001028
ROD: EV_AirbaVW10BPAVN750.rod
VCID: 3D27359D0DF45462A47-8068

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285) Labels:| 5K0-920-xxx-17.clb-SRI1
Part No SW: 7E0 920 970 S HW: 7E0 920 970 S
Component: KOMBI H03 1107
Serial number: 00000000000000
Coding: 450B000300
Shop #: WSC 02762 790 50316
ASAM Dataset: EV_Kombi_UDS_VDD_RM09 A05733
ROD: EV_Kombi_UDS_VDD_RM09_005_VW32.rod
VCID: 3A2D3E811CDA635A815-806E

1 Fault Found:
10486016 - Control module
B2001 00 [00001001] - Incorrect software version
[BAP: Steuerger t falsche Softwareversion]
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 5
Fault Frequency: 1
Reset counter: 84
Mileage: 250781 km
Date: 2024.10.01.
Time: 16:09:58


-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533) Labels:. 7E0-909-901.clb
Part No SW: 7E0 909 901 HW: 7E0 937 090 C
Component: GW-K-CAN TP20 H82 0752
Revision: B9082001
Coding: 042303
Shop #: WSC 02762 534 156453
VCID: 6889B4C9327621CA271-803C

1 Fault Found:
01304 - Radio
004 - No Signal/Communication - Intermittent
Freeze Frame:
Fault Status: 00100100
Fault Priority: 2
Fault Frequency: 3
Reset counter: 210
Mileage: 253112 km
Time Indication: 0
Date: 2019.07.25.
Time: 17:04:42


-------------------------------------------------------------------------------
Address 25: Immobilizer (J334) Labels:| 5K0-920-xxx-25.clb
Part No SW: 5K0 953 234 HW: 5K0 953 234
Component: IMMO H03 1107
Serial number:
Coding: 000000
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03710
ROD: EV_Immo_UDS_VDD_RM09_VW32.rod
VCID: 6A8DCEC12CFA13DA315-803E

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio
Cannot be reached

-------------------------------------------------------------------------------
Address 61: Battery Regul.
Cannot be reached

End----(Elapsed Time: 01:16, VBatt start/end: 11.7V/11.7V. VIgn 11.7V)-----
------------------------------9 Faults Found----------------

 

[HoopDub]

The electrical fault in circuit is because i had my multimeter in the circuit. I was trying to see if i had 12v when i initiated output test on the rear screen, it didnt work, still 6v

 

[HoopDub]

All sorted.

 

[Squiz]

Hiya I’d forgotten I had been following your thread as I am doing tailgate conversion too, just checked back to see if you had resolved the problem..good to see you did ! can you tell me how you did it ? Ta

 

[HoopDub]

Hiya I’d forgotten I had been following your thread as I am doing tailgate conversion too, just checked back to see if you had resolved the problem..good to see you did ! can you tell me how you did it ? Ta

I'd forgotten to connect the power from the fuse to the bcm

 

[Squiz]

Ah easily done !! Glad it went ok I’m 6 months in since fitting tailgate and still haven’t got around to the bcm wiring to lock and make other bits work hrw etc ! Maybe next month

 

[HoopDub]

Ah easily done !! Glad it went ok I’m 6 months in since fitting tailgate and still haven’t got around to the bcm wiring to lock and make other bits work hrw etc ! Maybe next month

My wiring had been hanging down for a good 6 months, finally got around to tidying it away last week. And as a thank you i split my head open on the tailgate and proceeded to spray claret everywhere. I have since fitted longer tailgate struts
Too many projects, not enough time.

 

[Squiz]

Ah yes that’s something I need to do which struts and where did you buy, we need t5 ones from memory ?

 

[HoopDub]

Ah yes that’s something I need to do which struts and where did you buy, we need t5 ones from memory ?

Yes T5 ones, I got these from Jeff

https://amzn.eu/d/0q3aFao

 

[Squiz]

Ace thanks ! Had some insuppa ones for my t4 they were great, will get jeff to send me some too ! Especially as i want to fit the Thule bike rack that seems to be filling my whole garage !Thanks again

 

[frizzuti]

I'd forgotten to connect the power from the fuse to the bcm

Hi there HoopDub,

I need to do the same as you’ve done here. Fitted heated tailgate window but not managed to finish the wiring.

I’ve got as far as installing the wires from either side of the window terminals. I had to bypass the T17 pin connector which sits in the roof above the LHS D-pillar because I’ve had a pop-top fitted and can’t access this connector as the new metal frame is in the way. As this is just a connector I figured it doesn’t matter.

I think, as it’s been over a year since I started and can’t remember, I have also bypassed the J9 relay (in the front passenger seat) - is this gonna be a problem? Assuming not, I’ve pulled the wires through to the dash (LHS) across and down RHS ready to connect into the BCM. I think I’ve attached the negative side wire to an earth point somewhere around the RHS wheel arch. So it’s just the positive wire to install.

I’ve also already purchased a new control panel with the rear screen heater button, connected this in and programmed the BCM using VCDS to tell it it now has a heated screen fitted. I’m assuming this is working as when I press the heater screen button it lights up and I also get a fault code (using OBDII) something like open circuit heater screen - which in its current state is correct, as the positive wire isn’t connected yet.

So on to connecting into the BCM and fuse box. Apart from being an almighty pain to access, I’ve managed to get to the BCM and someone else from this forum posted me some connector tails which I’m hoping I can just connect to my positive screen wire. The question is, am I correct in saying I need to connect into pin 73 KL30a of BCM then another connector with wire (2.5mm2) from pin 73 KL30 (out of the BCM) which if I’ve understood the wiring diagram right, goes to the Fuse holder C, SC20 into posn 20 and is a 30A standard size fuse? Then with a fuse in place this should work?

I’m yet to release fuse holder C to access the rear of it but have seen how from another post - but I know it’s tight. Did you manage to connect into the SC20 posn without having to remove the fuse holder C completely, which I think can only be achieved if you remove the entire dash?

Also with the pin connectors, again I’ve seen another post stating which ones I need - is it definitely the larger one for a standard blade fuse?

Sorry for the long reply but I don’t want to start taking everything apart again without knowing I can complete the job.

I’ve attached a few photos from the other posts of the posn of Fuse holder C and posn 20…is this the right one?