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71

General Discussion / Re: BMW Switchgear wiring

« Last post by karlh on October 08, 2025, 12:25:11 PM »

@carlh Thank you.  LIN bus is new to me. I will need to get smart on that.  Any idea why 3 wires - 12v, 7v, and 7v would be going to the left-hand switchgear?

Your switch cluster probably contains a small microprocessor that communicates switch actions to a central control unit.  Just like CAN, this simplifies wiring by only requiring the three wires you described instead of individual wires for each switch.

72

General Discussion / Re: BMW Switchgear wiring

« Last post by botus on October 08, 2025, 10:55:09 AM »

@botus Thank you. It is not a new switchgear.  I dismantled the switchgear housing and replaced the plastic thumb controls for cruise on/off and set/resume. Cruise control works fine now.  However, the horn and turn signals stopped working.

so all the wiring and all the switches are original and should be 100% normal - so either didn't re connect or now something is broken

double check the internet - were some of the R18s switchgear's faulty from birth - I seem to recollect hearing that

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General Discussion / Re: BMW Switchgear wiring

« Last post by tngarren on October 08, 2025, 01:09:17 AM »

@carlh Thank you.  LIN bus is new to me. I will need to get smart on that.  Any idea why 3 wires - 12v, 7v, and 7v would be going to the left-hand switchgear?

74

General Discussion / Re: BMW Switchgear wiring

« Last post by tngarren on October 08, 2025, 01:07:01 AM »

@botus Thank you. It is not a new switchgear.  I dismantled the switchgear housing and replaced the plastic thumb controls for cruise on/off and set/resume. Cruise control works fine now.  However, the horn and turn signals stopped working. 

75

General Discussion / Re: BMW Switchgear wiring

« Last post by karlh on October 07, 2025, 11:13:04 PM »

Your voltages suggest the communication from the switch cluster is via a LIN bus, not CAN.  CAN voltages usually top out at around 3.5 volts, while LIN voltages are higher.

76

General Discussion / Re: BMW Switchgear wiring

« Last post by botus on October 07, 2025, 07:51:50 PM »

2021 R18 but topic would generally apply to all CAN bus BMWs. 

I had to replace the plastic cruise control controls on the left-hand switchgear.  Like most of my work, I fixed one thing and broke another.  Now the cruise control works, however, the horn and turn signals stopped working.  The other functions on the switchgear work - cruise control, flashers, high beam, menu, aux lights. 

All the functions run off 3 CAN bus wires - 12V, CAN L, and CAN H.  They are getting 12V, 7V, 7V to ground with ignition on.  So, I am thinking the problem is on the switchgear.

I have disconnected the battery to reset the bike control units but no help. 

Is there a way to read the CAN bus data to see if the horn and turn signal buttons are sending any data?

Any other diagnostic advice is appreciated.

Pic attached.  Four circled buttons are left, cancel, right.  Bottom is horn.

https://imgur.com/a/XSyNCBs

did you dismantle the switch or swap the entire thing ?

if you swapped it out - is the new one OK - everything plugged in - maybe plug in the old one and see where you are - no need to mount it to the bike

these things are strange and sometimes multiple versions exist - dependant upon the toys on a given bike -
on my GS they all behave differently but you'd think they were all compatible parts - they are not - they don't just switch - they use weird beard different resistances and magically different wires connected up inside to the multiplug

you must match the exact same part number

example

01    Combination switch left       1          61319467929    (says cruise)
01    Combination switch left       1          61319467931    



https://www.realoem.com/bmw/en/showparts?id=0L11-EUR-04-2021-K34-BMW-R_18_0L11,_0L13_&diagId=61_6744






 

77

General Discussion / Re: BMW Switchgear wiring

« Last post by schuppi on October 06, 2025, 11:20:37 PM »

# I cannot sniff the real time CAN buss data packets #

Sorry,
This is not possible
other devices would be required.

78

General Discussion / Re: BMW Switchgear wiring

« Last post by tngarren on October 06, 2025, 11:07:14 PM »

I am sorry, I do not understand.  I can see some real time values like temperature and horn on, etc. with my GS-911. However, I cannot sniff the real time CAN buss data packets.

79

General Discussion / Re: BMW Switchgear wiring

« Last post by schuppi on October 05, 2025, 11:51:54 PM »

Hello

This is what the GS911 is designed for.
Here you can read the real-time data in the Body Controller Lite XBCL and check its functionality.

80

General Discussion / BMW Switchgear wiring

« Last post by tngarren on October 05, 2025, 08:08:23 PM »

2021 R18 but topic would generally apply to all CAN bus BMWs. 

I had to replace the plastic cruise control controls on the left-hand switchgear.  Like most of my work, I fixed one thing and broke another.  Now the cruise control works, however, the horn and turn signals stopped working.  The other functions on the switchgear work - cruise control, flashers, high beam, menu, aux lights. 

All the functions run off 3 CAN bus wires - 12V, CAN L, and CAN H.  They are getting 12V, 7V, 7V to ground with ignition on.  So, I am thinking the problem is on the switchgear.

I have disconnected the battery to reset the bike control units but no help. 

Is there a way to read the CAN bus data to see if the horn and turn signal buttons are sending any data?

Any other diagnostic advice is appreciated.

Pic attached.  Four circled buttons are left, cancel, right.  Bottom is horn.

https://imgur.com/a/XSyNCBs