Keyless, Central Locking, Fuel Filler Cap

[gogs01]

I've put this in the "electrical system" because I THINK my problem is electrical .....


My 2016 R1200RT LE has keyless and central locking. With the central locking engaged, the fuel filler cap is locked.  When the bike stops and the ignition switched off, the fuel filler cap unlocks for a short time to allow refuelling, automatically re-locking.


When my bike was serviced at my local BMW dealer, the tech noted that my fuel filler cap was not locking.  A new filler cap assembly is expensive and the filler cap still closes and seals, so I decided to investigate at a later date. I have taken the assembly out, checked that everything can move, sprayed with contact cleaner and re-assembled. No change.  Removed it again, traced the electrical lead back to the connector and took that apart. Using a multimeter I measured 12v across the connector which did not change when locking or unlocking the central locking.  I'm now stumped and reluctant to ask the dealer to fix it because I worry they'll change the assembly when it may be an electrical (electronic ?) fault.


Any suggestions ??

[PeteM]

I don't believe the petrol filler is linked to the central locking, so rather than checking for voltage change when locking/unlocking you need to check for voltage change when key is out of range after however many seconds.

[gogs01]

I don't believe the petrol filler is linked to the central locking, so rather than checking for voltage change when locking/unlocking you need to check for voltage change when key is out of range after however many seconds.

OK - thanks, that's my job for tomorrow then .....

[gogs01]

OK, plastics removed and connector for fuel filler cap central locking separated.
I measured constant battery voltage across the socket regardless of ignition on or off, central locking engaged or not, key in range or not.  I have to believe there is a "signal" fault.


I checked the socket for the left side "glove box" and it gives a zero reading until I engage the central locking, when it kicks up towards +5v. Disengaging the central locking sees the needle kick downwards (-ve).  It would make sense to me that both items should work in the same manner, but I'm not brave enough to connect the supply for the glove box to the fuel filler cap - it may not be that simple .....


Re-reading the owner's manual, the only influence the key has is that it will allow you to unlock the fuel filler cap if the key is within range.  It says nothing about getting it to lock, other than it should lock two minutes after ignition off.


S0 - any auto electrical whizz kids have any idea how to fix this ?