CANbus Questions

[BobsST]

I installed a second power outlet using the factory kit and stubbed out CANbus wiring socket located close to the preload adjuster on my ST. This weekend I was trying to run two vests at about 3.5 amps each which did not seem to work. I was hoping that when the manual said not to exceed 5 amps it was per outlet and not total load but I guess that's not the case. Has anyone else run into this? Also, is it correct to assume that if you trip the CANbus you have to 're-boot' to get the outlets hot again?? I'll probabaly end up installing a third outlet direct to the battery so we can have a second vest and also use the Battery Tender.

 

Thanks - Bob

[deltaBMW]

Bob, I ran a Gerbings jacket at full blast this weekend w/o problems and I think it draws more than two vests. I have the second outlet at the tail installed at the factory. Now I wondering if I can tap into it to also power an autocom.

 

fletcher clark

06 R1200RT

[TowJam]

I installed a second power outlet using the factory kit and stubbed out CANbus wiring socket located close to the preload adjuster on my ST. This weekend I was trying to run two vests at about 3.5 amps each which did not seem to work. I was hoping that when the manual said not to exceed 5 amps it was per outlet and not total load but I guess that's not the case. Has anyone else run into this? Also, is it correct to assume that if you trip the CANbus you have to 're-boot' to get the outlets hot again?? I'll probably end up installing a third outlet direct to the battery so we can have a second vest and also use the Battery Tender.

Bob,

My RT has the standard equipped power socket as well as the factory installed optional socket. Although I don't have it in front of my, my owner's manual indicates that each socket is 5 amps. I would think that the same would hold true for the ST.

[steve.foote]

My RT has the standard equipped power socket as well as the factory installed optional socket. Although I don't have it in front of my, my owner's manual indicates that each socket is 5 amps. I would think that the same would hold true for the ST.

 

On the GS, it's 5amps for the both of them. They are wired in parallel off of the rear outlet feed from the CAN BUS

[BOOCH]

Bob,

I asked a similar question regarding my R1200Rt.I was hoping that one of the long time BMW insiders (Fernando-Paul) would respond,but they did'nt.

Guys with OTHER than CANBUS bikes and solo riders need not respond. This is an issue of two heated items being used at the same time....

Steve

[MattS]

long time BMW insiders

Well, Rightspin here is a schmuck ... and so am I, apparently.

 

Despite these shortcomings, we can say with confidence that three point five plus three point five is way more than five, probably more like seven or something.

[Jim VonBaden]

long time BMW insiders

Well, Rightspin here is a schmuck ... and so am I, apparently.

 

Despite these shortcomings, we can say with confidence that three point five plus three point five is way more than five, probably more like seven or something.

 

 

Jim

[Buster]

My understanding is that the GS and ST are limited to a total of 5 amps, whereas the RT is allowed 10 amps. Not "per socket" but total amperage drawn from either or both at the same time.

 

I'm running a jacket liner and gloves (total of about 100 watts) out of the front socket on my RT and it works just fine.

 

I'm going to learn a lot more than I now know about this CANbuss before I start tapping into its circuits. There are electrons flowing around in there with certain jobs to do and confusing them might have serious consequences for the proper operation of other systems on the bike.

 

"I got some wire cutters and a soldering iron and headed for my HexHead" What could possibly go wrong?

 

Buster

[David_S]

Why not just run the rear socket to the battery and be done with it? Then you'll have a socket that will work and a place to connect a battery tender or other normally priced charger.

[Scarver]

Ran into this problem yesterday while on a ride. Have Gerbing jacket liner AND heated gloves through a controller connected to front accessory outlet. Tapped the lines going to the BMW Navigator socket to supply power for my Garmin 2610.

 

Heat and GPS suddenly 'died' while riding. At next stop turned GPS off and turned engine off as well. Restarted engine and heat came back on. Later, when it warmed up, disconnected gloves and was able to use jacket and GPS combined.

 

Does anyone have the circuit diagram for the R1200RT to see if the BMW Navigator circuit is tied into the front accessory CANbus thereby reducing the maximum drain from that outlet?

[RichEdwards]

On the '05's, be done with it and install a fuse box that is hooked up to the battery and forget about Canbus/accessory problems. It's an easy installation and many here have done it.

[EffBee]

Bob,

I asked a similar question regarding my R1200Rt.I was hoping that one of the long time BMW insiders (Fernando-Paul) would respond,but they did'nt.

Steve, sorry but I don't know the answer. However, here are some things to consider.

 

The variable heat controllers on most of these clothing items are actually variable-width timers. In other words, they constantly turn on and off, altering the length of the on/off cycles to create more heat or less heat. A Gerbing jacket liner is rated at 77 watts, or about 6.4 amps. A Gerbing, BMW or Widder vest is going to pull about 44 watts, or about 3.6 amps. But these loads are only spike loads, when the controller is on (which is about once per second).

 

The Acc ports on the CANbus bikes are not specific-load protected but are max-load protected. Typically, when using heated clothing with a good jacket on top, you don't dial up the controller much more than about 1/3 power, which means the jacket is drawing power for 1/3 second and is off for 2/3 second. Therefore, drawing enough power to get the system to shut power off to the Acc port is not very likely. The BMW vest does not come with a controller, but an on/off switch. At 3.6 amps, it's not likely to cause an overload shutoff.

 

Gerbing has recently announced, and I believe this would apply across the board to all port-powered accessories, that they recommend you have your gear plugged in to the BMW Acc port and turned to "on" before you turn on the ignition key. I would also add that you might want to give the system a second or so after you turn on the key before you start the engine. This gives CANbus a chance to recognize the Acc port and verify its load is within parameters.

 

Again, I could be all wet, here. I'm not a BMW-trained technician so don't take my word for any of this. Like I said above, I don't KNOW the answer. But given what I've picked up about CANbus, it makes sense to me..

[cjmkerns]

My Widder Vest, MIFI and cell phone are all on the front socket circuit of my 12RT. No problems there. But my little air compressor (for emergencies) and battery tender are a problem with the CANBUS.

 

I have a rear accessory socket but wanted to keep it as is, on the CANBUS, for other goodies or passenger use. I noted, however, that the plastic tail section was designed to accomodate a socket on the right side also. They just didn't drill the hole, so I did. Then I installed a third socket from Cycle Gadgets wired direct to the battery through a 15 amp weather protected in line fuse ($2 at AutoZone). Problems solved, I can run the little compressor and the battery tender is hooked up as I type. Good to go!

[lawnchairboy]

any pics of your installation?

[Ken H.]

Guys with OTHER than CANBUS bikes and solo riders need not respond.

OK don't read this reply then.

 

Geezzzz.

 

But for the sake of other readers who might like to know, on all the CAN-BUS bikes the accessory sockets are in parallel. That is the current limit is the combined load of whatever is connected to both of them.

[dyvking]

Bob, I ran a Gerbings jacket at full blast this weekend w/o problems and I think it draws more than two vests. I have the second outlet at the tail installed at the factory. Now I wondering if I can tap into it to also power an autocom.

 

fletcher clark

06 R1200RT

My GS only allows 5 amps total against the CAN-Bus. The manual for the RT is unclear, but I got the feeling it was the same. That being said, I wired my Gerbings power lead direct to the battery. That's the biggest draw I'll ever have. It's an easy do. I just stuff the lead under the seat when not in use. I stuck a small piece of dual-lock on the tank just above the front of the seat, and another piece on the back of the controller so it just pops on and off as needed.

That leaves plenty of juice to run just about anything else you can think of.

[MattS]

But given what I've picked up about CANbus, it makes sense to me.

Sounds reasonable to me. But talk about being put on the spot.

 

I mean, it's not like there isn't a wealth of information available on this topic, culled from the collective two (well, almost two) years that that the CANBUS system has been in the product line. A lot of specific answers to a lot of specific questions. Questions like these.

 

You would think that a little bit of research would go a long way. Or not.

 

Back on topic, if the GS aux ports are rated at 5A, and at 10A on the RT ... is it possible to software-modify that rating? So far, I think, the 5A/10A theory remains hypothesis, but is consistent with the RT's mission as a two-up tourer. Also, is the rating the kind of upper limit beyond which the charging system may not be performing optimally? Battery failures are too common to be well documented (imagine that), but I've anecdotally noticed many here, and they almost always involve a bevy of high-dollar, high-current accessories. Not that I'm not guilty, insofar as my Gerbings lead goes direct-to-battery, but it's an interesting concept.

 

Can of worms, meet internet. Internet, can of worms.

[Tom B]

Bob

 

Maybe one of these http://www.autocom.co.uk/pdf/158.pdf will help?

 

Tom

[Ken H.]

is it possible to software-modify that rating?

Sure it would be easily possible if we had access to it. But the point of the software limit, like that of a conventional fuse is to limit the current to the rated limit of the wiring. Just like putting in a bigger fuse than what is called for you would run the risk of overloading the wiring. Remember the purpose of a fuse is not to protect the device (e.g. a GPS or a heated vest, whatever) it is to protect the wiring from the device(s).

Also, is the rating the kind of upper limit beyond which the charging system may not be performing optimally?

No. The primary purpose is to protect the wiring of the bike. Larger wiring = bigger fuses / current limiting. Smaller wiring = smaller fuses / lower current limits.

[MattS]

Good stuff, Ken.

 

Back to the 5A/10A GS/RT thing ... if that is so, is it possible/probable that the wiring to the sockets is beefier on the RT?

[Ken H.]

is it possible/probable that the wiring to the sockets is beefier on the RT?

If it was my bike and I was dead set on using the sockets themselves (vs. some other type of power connector) I would replace them with heavier duty ones from Powerlet and run them directly from the battery. (Fused of course.) Skipping the whole CAN-BUS limiting thing all together. If you wanted them to switch on/off with the ignition, relay them from the (now not used) connection to the original socket.

[BobsST]

Wow - thanks for all the help everyone. I can see that this is kind of a grey area. I'll use the CANbus outlets for the small stuff and add another fused outlet direct to the battery. Again, thanks for the help - Bob

[RFW]

long time BMW insiders

Well, Rightspin here is a schmuck ... and so am I, apparently.

Odd choice of words! Schmuck is German for Jewellery.

 

Bob.

[Marty Hill]

Matt,

 

Be careful who you teach how to add...knowledge can be dangerous.

[jaySTrider]

I've just had problems with my Stormrider vest tripping the system on my ST. I've spent the day replacing one of the sockets with a Powerlets one direct to the battery via a fuse to cope with the vest and moved the spare auxilary canbus socket to the front inner fairing to run my gps.

 

I can't see why BMW would have a separate rating for the RT compared to the GS and ST - it must make sense to standardise on the wiring looms across the range.

[steve.foote]

Well, Rightspin here is a schmuck ...

 

Damn, I didn't think anyone knew. Obviously, there is no keeping secrets on the internet.

[cjmkerns]

I got pics.

 

See attached.. outside, Battery Tender attached.

 

Carl

[cjmkerns]

Attached.. inside (Powerlet from Cycle Gadgets).

 

 

Carl

[cjmkerns]

And last.. weather protected inline fuse.

 

 

Regards,

 

Carl

[BOOCH]

Fernando,

Thank you for entering the fray.Your input plus that from all the others that stayed on point,are invaluable.

It's a shame that BMW took two GIANT steps forward with the design of the R1200RT and one LARGE step backwards with this CanBus system.To be forced to have factory power ports rewired so you can use them for their intended purpose,is ridiculous.

Thanks to all

Steve

[steve.foote]

Booch,

 

Why do you think the CANbus is a big step backwards? It reduces weight, is easier to maintain (requires no physical fuses) and provides more functionality than a traditional wiring system.

 

The 5 or 10 amp limit is a software parameter established by BMW for reasons yet to be discovered. The disappointment is not that BMW installed a CANbus system, but that they set the accessory outlet amperage so low.

[PaulW42]

When Autocom installed the power supply, they created an occasional short circuit. For a variety of reasons, it took a long time to trace. That was the Thank Heavens for CANBUS moment, as I would have run out of fuses long before I found the source of the problem. With CANBUS I just had to reset.

 

The unnerving moment was I found that you could get the wiring to start pouring out smoke for 1 -2 secs before the CANBUS killed the current! This was on a 10 amp RT. Anybody fancy trying it on a GS or ST?

 

BTW so far I have run Autocom, GPS and heated vest at the same time with no problems but I think the real test will be when a second vest/jacket is added to the mix.

 

Paul

[Ken H.]

Yes, that's exactly the best approach to take. Nice work.

[smiller]

Why do you think the CANbus is a big step backwards? It reduces weight, is easier to maintain (requires no physical fuses) and provides more functionality than a traditional wiring system.

 

The 5 or 10 amp limit is a software parameter established by BMW for reasons yet to be discovered. The disappointment is not that BMW installed a CANbus system, but that they set the accessory outlet amperage so low.

I don't know if CANbus is a step backwards but there is a potential downside for those who self-service their bike in that I don't see how one could troubleshoot the system very deeply without BMW special tools and support. The advantages of CANbus just aren't that significant in my mind but potential owner-servicing issues are of great importance to me.

 

To be fair perhaps this won't be a problem in the real world (just as ABS and Motronic issues haven't ended up being particularly problematic on the oilheads), but I personally need to see some more time put on the system to be sure that it will not tie me to dealer support in some unanticipated way. So far so good but...