2013 6R Polo Remote Locking Oddity & Root Cause

   #1  

nugentp

Verified VCDS User
Verified
Joined
Jan 3, 2019
Messages
176
Reaction score
76
Location
UK
VCDS Serial number
C?ID=353561
This took me a few/five hours to root cause so thought it worth sharing for any other poor soul that gets into same situation.
This is a daily driven car that has never given any electrical woes.

Code:
Address 09: Cent. Elect. (J519)       Labels:. 6R0-937-08x-09.clb
   Part No SW: 6R0 937 087 K    HW: 6R0 937 087 
   Component: BCM PQ25 H+4  H46 0254  
   Revision: BF046001    Serial number: 0434 266121636
   Coding: 25B029BF08A1000001280EC02DAB0ED8B00041FF60060000200000000000
   Shop #: WSC 12469 483 00190
   VCID: C5C2D5B84CD9426754-8091

   Subsystem 1 - Part No: 1K0 955 559 AH  Labels: 1K0-955-559-AG.CLB
   Component: RLS 210912 05  54  0403 
   Coding: 03302D

   Subsystem 2 - Part No SW: 6R0 959 802 AB    HW: 6R0 959 802 AB  Labels: 6R0-959-802.CLB
   Component: J386__TSG_FT  008 1621 
   Serial number: KU0KU020091200018422
   Coding: 18BC30

   Subsystem 3 - Part No SW: 6R0 959 801 AD    HW: 6R0 959 801 AD  Labels: 6R0-959-801.CLB
   Component: J387__TSG_BT  008 1621 
   Serial number: KU0KU017091200010077
   Coding: 18BC30

   Subsystem 4 - Part No SW: 5K0 959 542 C    HW: 5K0 959 542 C
   Component: E221__MFL-TAS  H31 0033 
   Serial number: 0285424             
   Coding: 020000

No fault code found.
------------------------------------------------------------------------------------

8am - car would not start - flat battery - most likely cause being some accessory left on overnight.

9am - put charger on the battery while on the vehicle to let that do its work and hope for no permanent damage to battery.

10am - discovered the accessory that most likely source of battery drain (long story short it had been wired up to a permanent supply, not switched)

3pm - had the accessory wired up the right way after much careful trim removal and connectorised cabling. All tested and looking good. Went to lock the car with remote key fob and it didn't work. Used the mechanical key and that was all fine. Car started fine too - with both keys. Shutdown and key fob would lock the car - seems like they were just out of sync. Walk away for few mins, come back and neither key fob would unlock the car. Repeated this a few times thinking I was going mad... then read the actual owners manual and tried the key sync procedure documented there. Both fobs would lock and open the car if pressing buttons within 30-60 seconds of taking key out of the ignition.

5pm - googled about and looked up VCDS methods for resetting/adding key fobs

7pm - came back to the car ready to flush both keys and add them again... noticed the battery was well charged at this point so unplugged the charger and closed the bonnet (hood) - THEN it dawned me there is a microswitch in the bonnet lock and I wondered if the BCM was seeing that open and causing this odd behaviour. Tried both keyfobs again and all locking/unlocking working as normal. To prove I wasn't going mental, I opened the bonnet and tried the key fobs again - with time delays and from decent distance - again all good.

8pm - THEN I remembered seeing mention of a battery condition monitor function in the BCM/CCM, so I reconnected the battery charger and recreated the key fob chaos where they would stop working after ~30s. Disconnected the charger and closed the bonnet - all 100% good again.

==> ROOT CAUSE - The BCM/CCM on the 6R must have some 'feature' that disables the use of key fobs for locking or unlocking the car when it detects the battery is on charge (and bonnet is open). Had I known that almost 5hrs ago then I would have been able to enjoy more of the sunshine. Anyway, such is life - recording all this VW electrical / software annoyance is my good deed for the day - May the 4th be with you.
 
Last edited by a moderator:
Top