Patil's little Polo 6R 1.2 Tsi Dsg7 RHD

[patil]

Ok, here are some details of blowing SB21 fuse in my 6R in chronological order.

Background:
1st incidence: Wife complaint to me that none of the interior lights are working. When I checked, SB21 was blown( 15A fuse from factory), I didn't investigate nor did a scan, thinking that I will have a look in free time so just replaced the fuse and all lights started working again.

2nd incident: After 3 days of 1st incident, Wife went out with kids for shopping and came back complaining that boot is not opening now! She didn't say anything about lights. When I checked, all interior lights out, boot was not unlocking and a bulb out warning lamp was lit in cluster( 1st time I simply didn't notice?) . This time I did a thorough check, did a scan which I am posting below.

Following were not working:
1. All interior lights not working
2. Door warning lights not working ( power was taken from t73a/65 so it was obvious)
3. DRL's and parking lights( front and back) were not working
4. Boot was not unlocking.

First two not working is understandable but 3rd and 4th not working surprised me a bit.

Here is the autoscan:

Code: Select all

Wednesday,21,June,2023,22:47:37:09269
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 x64
VCDS Version: 23.3.1.0 (x64)  HEX-V2 CB: 0.4631.4
Data version: 20230421 DS346.2
www.Ross-Tech.com


VIN: MEXL15606GT048293   License Plate: 


Chassis Type: 60-VW25 (7E0)
Scan: 01 02 03 04 08 09 10 15 17 19 20 25 37 3C 44 55 5F 65 77

VIN: MEXL15606GT048293   Mileage: 113730km-70668miles

01-Engine -- Status: OK 0000
02-Auto Trans -- 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: Malfunction 0010
15-Airbags -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
20-High Beam Assist. -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
37-Navigation -- Status: OK 0000
3C-Lane Change -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
55-Headlight Range -- Status: OK 0000
5F-Information Electr. -- Status: Malfunction 0010
65-Tire Pressure -- Status: OK 0000
77-Telephone -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (J623-CBZB)       Labels:. 03F-906-070-CBZ.clb
   Part No SW: 03F 906 070 KC    HW: 03F 907 309 AJ
   Component: SIMOS10.22AH10 6270  
   Revision: --H10---    Serial number: 00000000000000 CVN: 461B84FC
   Coding: 00250056232400080000
   Shop #: WSC 53863 002 104857
   ASAM Dataset: EV_ECM12TFS02103F906070KC 004006
   ROD: EV_ECM12TFS02103F906070FP.rod
   VCID: 6D84C0CEAD13BD32D4D-8038
   VINID: 755A1C0451801979001080890C0D0C61A9

No fault code found.
Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 0AM-927-769.clb
   Part No SW: 0AM 300 065 N    HW: 0AM 927 769 D
   Component: GSG DSG AG7     431 6502  
   Revision: 00043014    Serial number: CU501508317273
   Coding: 0000020
   Shop #: WSC 01260 002 1048576
   VCID: 3A2E3B92A05DDA8A01F-806E

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 6R0-907-37x-ESP90.clb
   Part No SW: 6R0 907 379 CB    HW: 6R0 907 379 AS
   Component: ESP9.0i front H03 0003  
   Serial number: --------------
   Coding: 62DD2863422703C8461614724254C0800908
   Shop #: WSC 29230 002 104857
   ASAM Dataset: EV_Brake1ESP90iBOSCH 003031
   ROD: EV_Brake1ESP90iBOSCH_003_VW21.rod
   VCID: 005A897A8A81405A0FB-8054

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: 07022013470235
   Coding: 01
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_LWSKLOVW25X 005001
   ROD: EV_LWSKLOVW25X.rod
   VCID: 7EA6F782F07536AA7D7-802A

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J255)       Labels: 6R0-907-044.clb
   Part No SW: 6R0 907 044 Q    HW: 6R0 907 044 Q
   Component: Climatronic   H12 0615  
   Revision: V0000000    
   VCID: 41DC4C7EC18B8952405-8014

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 7E0-937-BCM-V1.clb
   Part No SW: 7E0 937 090 D    HW: 7E0 937 090 D
   Component: BCM PQ25 Max4 H82 0762  
   Revision: B9082001    Serial number: 8601 222180475
   Coding: 3AB02FF808210000213806D17CCB9ED0F2C0670F604D30C0200400030800
   Shop #: WSC 00046 123 12345
   VCID: 2C020DCA5609743A833-8078

   Subsystem 1 - Part No: 5K7 955 547 
   Component: RLHS 200618 0  50  0107 
   Coding: 0228DD

   Subsystem 2 - Part No SW: 6R0 959 802 BH    HW: 6R0 959 802 BH  Labels: 6R0-959-802.CLB
   Component: J386__TSG_FT  003 8612 
   Serial number: KU0KU015041441050460
   Coding: 1400B3

   Subsystem 3 - Part No SW: 6R0 959 801 BC    HW: 6R0 959 801 BC  Labels: 6R0-959-801.CLB
   Component: J387__TSG_BT  003 8612 
   Serial number: KU0KU014041441047765
   Coding: 0400B3

   Subsystem 4 - Part No SW: 5TA 959 442     HW: 5TA 959 442 
   Component: E221__MFL-TAT  H04 0019 
   Serial number: 2731410180700922AG1B
   Coding: 270000

   Subsystem 5 - Part No SW: 6R0 959 811 L    HW: 6R0 959 811 L
   Component: -------------  006 5550 
   Serial number: 13102580150623202239
   Coding: 020000

   Subsystem 6 - Part No SW: 6R0 959 812 L    HW: 6R0 959 812 L
   Component: -------------  006 5550 
   Serial number: 13202581150812164218
   Coding: 020000

4 Faults Found:
03434 - Output for Terminal 30G Interior Lights 
            007 - Short to Ground
             Freeze Frame:
                    Fault Status: 01100111
                    Fault Priority: 3
                    Fault Frequency: 6
                    Reset counter: 75
                    Mileage: 113724 km
                    Time Indication: 0
                    Date: 2023.06.21
                    Time: 19:46:47

03435 - Terminal 30 for Interior Light and Parking Light 
            011 - Open Circuit - Intermittent
             Freeze Frame:
                    Fault Status: 00101011
                    Fault Priority: 3
                    Fault Frequency: 2
                    Reset counter: 115
                    Time Indication: 0

02745 - Bulb for Daytime Running Light; Left 
            010 - Open or Short to Plus - Intermittent
             Freeze Frame:
                    Fault Status: 00101010
                    Fault Priority: 3
                    Fault Frequency: 3
                    Reset counter: 115
                    Mileage: 113724 km
                    Time Indication: 0
                    Date: 2023.06.21
                    Time: 19:54:56

02746 - Bulb for Daytime Running Light; Right 
            010 - Open or Short to Plus - Intermittent
             Freeze Frame:
                    Fault Status: 00101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 113724 km
                    Time Indication: 0
                    Date: 2023.06.21
                    Time: 19:55:11


-------------------------------------------------------------------------------
Address 10: Park/Steer Assist (J446)       Labels:| 5Q0-919-294.clb
   Part No SW: 1K8 919 472 C    HW: 5Q0 919 294 A
   Component: PARKHILFE 8K  H03 0480  
   Revision: --------    Serial number: 39331616005272
   Coding: 0001151011
   Shop #: WSC 12345 123 12345
   ASAM Dataset: EV_EPHVA18VW364GP00 001007
   ROD: EV_EPHVA18VW364GP00_VW32.rod
   VCID: 372822A69FCFC7E2FE1-8062

1 Fault Found:
12718592 - Databus 
          U1121 00 [008] - Missing Message
          [Steuergerät für Lenksäulenelektronik-J527/BCM - mZAS_1 - kein Signal/keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 72
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 01:50:24


-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 5K0-959-655.clb
   Part No SW: 6R0 959 655 J    HW: 6R0 959 655 J
   Component: VW10AirbagU06 H10 0020  
   Revision: --------    Serial number: 003GW0118WCJ Dataset Number: 00000000000 0001
   Coding: 003036
   Shop #: WSC 01234 785 00200
   ASAM Dataset: EV_AirbaVW10BPAVW250 A01001
   ROD: EV_AirbaVW10BPAVW250_VW25.rod
   VCID: 49CC545EF93B4112985-801C

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5K0-920-xxx-17.clb-SRI1
   Part No SW: 6RD 920 870 A    HW: 6RD 920 870 A
   Component: KOMBI         H04 0805  
   Serial number: 00000000000000
   Coding: 141C00
   Shop #: WSC 12345 123 12345
   ASAM Dataset: EV_Kombi_UDS_VDD_RM09 A04727
   ROD: EV_Kombi_UDS_VDD_RM09_004_VW23.rod
   VCID: 47C85266EF2FB7628E1-8012

1 Fault Found:
12658432 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Steuergerät für Reifendrucküberwachung: keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 254
                    Reset counter: 115
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 02:02:08


-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:. 7E0-909-901.clb
   Part No SW: 7E0 909 901     HW: 7E0 937 090 D
   Component: GW-K-CAN TP20 H82 0762  
   Revision: B9082001    
   Coding: 002304
   Shop #: WSC 00046 123 12345
   VCID: 688AB1DA8271981AA7B-803C

No fault code found.

-------------------------------------------------------------------------------
Address 20: High Beam Assist. (J844)       Labels:| 8S0-857-511.clb
   Part No SW: 7E0 857 511 G    HW: 7E0 857 511 E
   Component: FLA           H10 0003  
   Revision: AA001001    
   Coding: 0404010000000000000000
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_HighBeamAssisAU316 001004
   ROD: EV_HighBeamAssisAU316.rod
   VCID: 2E0607C26095062AAD7-807A

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 0805  
   Serial number: 00000000000000
   Coding: 000000
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03710
   ROD: EV_Immo_UDS_VDD_RM09_VW21.rod
   VCID: 6A8ECBD29CFDAA0AB1F-803E

No fault code found.

-------------------------------------------------------------------------------
Address 37: Navigation
Cannot be reached

-------------------------------------------------------------------------------
Address 3C: Lane Change (J1086)       Labels:| 5Q0-907-686.clb
   Part No SW: 5Q0 907 686 C    HW: 5Q0 907 686 C
   Component: HRE_Master    H12 0081  
   Serial number: 0529820662 Dataset Number: V03935258DF 0001
   Coding: 03031202
   Shop #: WSC 12345 123 12345
   ASAM Dataset: EV_HREntryHella 001028
   ROD: EV_HREntryHella_VW37.rod
   VCID: 3D24308EBDF3EDB224D-8068

   Lane change assistance control module 2: 
   Subsystem 1 - Part No SW: 5Q0 907 685 C    HW: 5Q0 907 685 C
   Component: HRE_Slave  H12 0081 
   Serial number: 0530916291          
   Coding: 030312

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist (J500)       Labels:| 1Sx-909-144-44.clb
   Part No SW: 1S2 909 144 P    HW: 1S2 909 144 P
   Component: EPS_ECU       H61 1702  
   Dataset Number: 6RF074v____ 0120
   Coding: 0001000000000000
   Shop #: WSC 12345 123 12345
   ASAM Dataset: EV_SteerAssisNSK 014008
   ROD: EV_SteerAssisNSK_014_VW12.rod
   VCID: 41DC4C7EC10B8952405-8014

No fault code found.

-------------------------------------------------------------------------------
Address 55: Headlight Range (J431)       Labels:. 6R0-907-357.clb
   Part No SW: 6R0 907 357     HW: 6R0 907 357 
   Component: LWR-ECU       H02 0070  
   Revision: --------    Serial number: -------------- Dataset Number: 5c0036v____ 0004
   Coding: 0116000001000000
   Shop #: WSC 12345 123 12345
   ASAM Dataset: EV_HeadlRegulVWLWRPt 001004
   ROD: EV_HeadlRegulVWLWRPt_VW25.rod
   VCID: 77A8E2A6DF4F07E23E1-8022

No fault code found.

-------------------------------------------------------------------------------
Address 5F: Information Electr. (J794)       Labels:| 5G0-035-MIB-STD2.clb
   Part No SW: 5C0 035 680 F    HW: 5C0 035 680 F
   Component: MU-S-N-ER     H41 0478  
   Serial number: VWZAZ2U0986183 Dataset Number: V03935266VJ 0001
   Coding: 02620001FF0000005111000101080A001F0100D6002001004E
   Shop #: WSC 00046 123 12345
   ASAM Dataset: EV_MUStd4CTSAT 001022
   ROD: EV_MUStd4CTSAT_VW37.rod
   VCID: 2412E5EA3E59BC7A4B3-8070

   Data carrier: 
   Subsystem 1 - Part No SW: 5NA 919 866 CM    HW: -----------
   Component: MRM2 2023  --- 1910 
   Serial number: --------------------

4 Faults Found:
1556 - Internal Control Module Memory Check Sum Error 
          B2000 87 [009] - Missing Message
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 72
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 01:59:51

                    Voltage terminal 30: 13.0 V
                    System_Software_Error-SW_Status_Consistency: 04 01 01
                    System_Software_Error-SW_Status_Device: o

15360768 - Component Protection 
          U1101 00 [009] - Active
          [Anti-theft protection - component protection active (0xEA6300)]
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 4
                    Fault Frequency: 1
                    Reset counter: 72
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 01:50:23

                    Voltage terminal 30: 12.0 V

2562 - Navigation System 
          B126C F0 [009] - Navigation Database Faulty
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 72
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 01:50:35

                    Voltage terminal 30: 12.0 V

0001 - Antenna 1 for Radio 
          B1119 13 [008] - Open Circuit
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 113
                    Mileage: 113588 km
                    Date: 2023.06.21
                    Time: 12:12:52

                    Voltage terminal 30: 11.2 V
                    Status of antenna 1 for radio-Antenna current: 0 mA
                    Status of antenna 1 for radio-Connection between radio and antenna amplifier: Open circuit
                    Status of antenna 1 for radio-Connection between antenna amplifier and antenna: Not available
                    Status of antenna 1 for radio-Reception level antenna 1: 0 dBµV


-------------------------------------------------------------------------------
Address 65: Tire Pressure (J502)       Labels: 3AA-907-273.clb
   Part No SW: 3AA 907 273 F    HW: 5Q0 907 273 
   Component: RDKBERU30     H04 0011  
   Serial number: 40000000058983 Dataset Number: rdkseditor  0204
   ASAM Dataset: EV_RDKBERU30 005005
   ROD: EV_RDKBERU30_005.rod
   VCID: 372822A69FCFC7E2FE1-8062

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone
Cannot be reached

End----------(Elapsed Time: 01:33, VBatt start/end: 12.1V/12.0V)-----------

looking at the faults in BCM, correct me If I have understood incorrectly.
1st fault - output for 30G Interior lights short to ground: It means that t73a/4 ground wire going to BCM for interior lights is getting short somewhere.

2nd fault: Terminal 30 for interior light and parking lights "open circuit" intermittent: This means both interior lights and parking lights are supplied by t73a/65 ( parking lights are also supplied by t73a/65? this is new to me!) so blown SB21 explains this open circuit error. I didn't understand clearly why it's intermittent

3rd and 4th fault: DRL left and right open or short to plus intermittent: This error is due to no power flowing to drls( short to plus). So drls are also supplied by t73a/65

I checked the output after removing the fuse from SB21, multimeter shows 0.45A. That's too less or am I not checking correctly?

I don't think fuse is blowing due to over consumption, because every time it blew, keeping high/erratic consumption in mind I increased the amperage of replaced fuse to 20,25,30 ... yet all blew. I feel something is triggering the short circuit in wirings of additional lights I have installed. I will start looking for bad wires, bad leds. So much additional wirings in my 6R.. don't know even where to begin with, it's like finding a needle in hay stack.

My RVC has a clean +30 supply from fusebox with 5A fuse. It works fine even when sb21 fuse is blown.

None of the above still can't explain why boot is not unlocking when SB21 fuse is blown.. I don't see any connection between both. I will open the boot trim and have a thorough look and report back

[ciclo]

Ah, ok, I anticipate that the problems lie with those Door warning lights that you installed.

Well, since we have a BCM 7E0, we look in erWin for a PQ25 model that installs this BCM, for example the Amarok 2017, and we look for the supply assignments for the T73a/66 input and the T73a/65 output.

As seen in the previous image, in addition to supplying power to the interior/entry lights, it also supplies power to the parking/side lights.

In the following image we verify that the DRL (TFL) are also powered by T73a/66 and by T73b/68.


Therefore, all the faults detected in the scan are totally logical and due to the fact that the SB21 fuse melts due to excessive consumption.

Stop powering 'those door warning lights' from T73a/65 immediately.

First problem solved.

---
Let's go with the second problem. Here will be the problem with the boot opening malfunction.
We must know which diagrams you used for the installation of those Door warning lights. Please, if possible, indicate a link to the installation.

I found this report, but there is no info on how the door exit/warning lights were connected. viewtopic.php?p=571724#p571724
Those T10 type connectors are not my favorite, and you also comment that you have to add some consumption using CANBUS LED bulbs or filament bulbs (it does'nt sound good).

I remember that I made a thread on how to connect them successfully, but I am not able to find it.
Similar to this viewtopic.php?p=583390#p583390 , https://www.youtube.com/embed/iggFFCC2F ... autoplay=1, but for all doors on the 6R, instead of the rear doors on the Golf7.5.
It consists of connecting the positive of the door warning/exit light to the positive of the WRM and the negative to the wire of the door contact switch (F). Easy, simple and very effective.
The door warning/exit light will turn on only and exclusively when the door is opened. The door contact switch closes the circuit when the door is opened.

---
That model of door warning lights you installed was used on the Polo_9N Europe, and other models. If you don't feel like removing the door panels again, you can install the reflectors that have the same dimension instead.

---
https://www.youtube.com/watch?v=IE1vlUDYfqc&t=7s

[patil]

So 7E0 BCM's t73a/65 indeed supplies parking lights and drls also.. thank you so much for confirmation.


My intention of using t73a/65 instead of +30 to feed door warning lights was to prevent battery drain if doors remain opened for long time. Atleast BCM will shut off these lights after 20 minutes of idle.

viewtopic.php?p=488807#p488807 Here is your post I did same like you said except for positive feed which was fed from t73a/65.

Well the door warning lights with canbus leds which I have installed years back are working well.





Never faced an issue as such. Today I turned on all extra lights I have retrofitted to see if SB21 blows.. nope it doesn't, after 20 min all lights went off. So I am not yet totally convinced that door warning lights are excessively consuming power and blowing SB21. I guess problem lies somewhere else.. I will start checking wirings and LEDs of these lights.

So coming to boot unlock issue:

I observe that, with SB21 fuse blown, if I try to open the boot by pressing logo, it only partially unlocks and gets stuck.
Looking at the WD, it looks like boot unlock mechanism has two locks with two separate circuits.
First lock releases the boot handle and second lock unlocks the boot. So in my case 2nd lock is malfunctioning!


Now I smell what possibly could have gone wrong at the tail.. a " human error" I will have to check something, I will be back.

[ciclo]

These dual-plate LED models tend to short-circuit easily when one of the plates touches the contacts structure of the original lamps.
At least, it's something I experienced a long time ago (they went to the trash), and it may not be your case, but some heavy bumps/pothoholes could cause this to happen due to strong vibrations...
It is better that the LEDs are encapsulated.

I'm glad you remember what was the human error for the issue of the trunk lid unlocking malfunction... ... then, if you want, you tell us what was your audacity and we will decide whether to laugh for a while...

Good luck with your investigations!

[patil]

Boot unlock malfunction issue resolved

These lamps with its messed up wiring was the reason behind boot unlock issue.





This is how everything is wired in tailgate.



At first I had installed trunk light with the help of Master himself many years back. Later I installed tail open warning lights by connecting to wires of trunklight. All looked good and everything worked like normal untill SB21 fuse blew and opened can of worms!

Only after looking at WD of tailgate locks, I got a clear grasp of underlying problem. The wiring harness I had prepared for tail open warning lights was all botched up. A simple multimeter checks proved that I am the guilty one

Once I got rid of all those lamps with it's wiring harness, the boot started to unlock normally even with blown sb21 fuse!
If wiring was the mistake, then boot unlock should have failed from the beginning itself and why it's failing only after SB21 fuse is blowing? The plausible explanation is, blowing SB21 fuse is shorting t73a/31 within the wiring harness of tail gate lamps, subsequently causing malfunctioning of boot lock mechanism. Because I had used canbus leds which work in any polarity, so they worked normally even when there was mistake in wiring, which went unnoticed back then.

All this goes to bin.


My overzealousness of adding more lights in car has caused all this mess here you go lesson learnt again.. I will replace the existing with new boot trim and be happy with trunk light only))

I have replaced the leds to stock incandescent bulbs in all door warning lamps. I will observe if SB21 fuse blows again. I hope it won't.. if it does then case reopen!

Thank you dear master for your valuable time and help..

[ciclo]

Brilliant! Well done. We will keep an eye on the corrections applied.
I hope your dear wife and lovely family can fully enjoy the 6R and don't have to suffer the inconvenience of the boot unlock malfunction.

I recently fixed a similar problem on my brother-in-law's 2006 BMW 5 Series in which the wiring splits/breaks right where it flexes inside one of the trunk lid support arms. Now my sister-in-law is super happy to be able to use the trunk to make routine purchases.


Thanks to you my dear Doctor, we have spent a good time trying to be fortune tellers or magicians to find out what was the problem.

[ag69]

Quite an effort to pin point issue. Must be equal to a complex operation.
Does these lights (which you removed) were T10 type?

A novice question - as dome light and footwell lights are (5W and 3Wx2 each)
So the way you added trunk light and then added 4 lights in boot door (and anything more) as long as they were less than 11W it should have not blown fuse, right?
Are these LED have any power ratings?

[patil]

Hi AG sorry for late reply, I am busy for past few weeks with many retrofits ongoing in my roc

You have asked a very good question regarding consumption of lights I've retrofitted in my 6R.

I have W8 dome light in front with four philips 1W 6000K T10 leds. Rest of other retrofitted lights like rear reading, trunk, door warning, boot warning, glovebox, bulbs etc.. are canbus led festoons from AliExpress presumably rated between 1W-5W.
Eg; image source from internet


Honestly I never calculated the total consumption of all these lights, which I should've done but never bothered as all were working well without any problems.

Though we could able to fix the boot unlock issue, the SB 21 fuse continued to blow even after we made corrections posted above, even with all led's replaced with stock bulbs.

The real reason for repeated SB21 blowing was lying somewhere else! Thanks to my dear wife for giving me a crucial clue It was with one my other retrofits
viewtopic.php?p=578617#p578617

I will post the details soon.

[patil]

SB21 fuse blowing issue in my 6R resolved permanently

Here was the root cause:
Before I started to wonder where to begin with, one random day my wife came and said, I've observed that the vanity mirror light sometimes doesn't work!!!





I found two mistakes from above pictures. The wiring was routed poorly, the wires were sandwiched between roof metal frame and sunvisor plastic lock, and with constant pressure and time, wires insulation got ripped off. Secondly, the cloth tape was not wrapped to sufficient length around wires.

So whenever the microswitch within the sunvisor was activated, the current passed from positive wire to GND wire and caused short circuit and blowing SB21.

Image courtesy of T4 forum


This time I routed the wires correctly and fixed the damaged wires with proper insulation.

Finally wife is very happy and I am at peace)))

[ciclo]

Good find (finally).

☮

[patil]

Thanks to you my dear Doctor, we have spent a good time trying to be fortune tellers or magicians to find out what was the problem.

Ha ha.. reminds me of duo.. SH and Dr W

I conclude, solving the curious case of blowing SB21 fuse in my little 6R in the apt words of SH.. " When you eliminated all which is impossible, then whatever remains, however improbable, must be the truth"

[ciclo]

Good sentence to take into account.

... please, my dear Doctor, you must enlighten me, I don't know who or what is/are 'SH and Dr W' (duo)... ?
... I am completely unaware of what you are referring to ... you have me totally baffled.

[ciclo]

Ahhh... OK, Arthur Conan Doyle.

(lately I'm improving my clumsiness )