2016 FLSTC Electrical Mystery...

[Fugawee]

I Surrender...I'm waving the White Flag.
A couple of weeks ago Myself and a Buddy went 50/50 on a 2016 FLSTC from another Guy, who was the only Owner.  He bought it new in 2015.  It is in Very Good Condition with 18000 miles on it, with Stage 1 upgrades, and a Vance and Hines FP3, as well as a Brand New, known to be Good Battery.  The Stage 1 upgrades were done by the Dealer shortly after Him taking delivery of it.  There is not a Security System on the Bike.  Only one minor problem...it won't start, or pretty much do anything.  The Engine is not seized, and no wiring hacked up.  We had planned on flipping it once this problem is solved, hopefully.  We are both somewhat familiar with the CANBUS, but not experts.

Here's the story...
Turning the Bike on from the Dash Panel, the Headlight comes on for a second and goes out.
The Speedo, and Oil/Neutral Light will stay on.  The Engine, ABS light, etc. in the Speedo stay lit.
The Left and Right Controls won't do anything meaning T/S, Horn, Start, Brake Light, etc.
You don't hear the Fuel Pump at all.
The onboard Speedo Diagnostics will work coming up with a U0001=CANBUS Error, on the ECM, BCM, ABS, and Speedo, and that's it.

I have a Centurian.  Hooking that up to the DLC it will say "No Voltage Seen.  Check Cables".
There are 12 Volts of Power to the DLC, and approx. 2.5 Volts on the White/Red, and White/Black Pins on the DLC.
Disconnecting the Black Connector at the ECM, there is 2.5 Volts on the CANBUS White/Red Wire, and 0 Volts on the CANBUS White/Black Wire.  Is that normal?
There is 12 Volts going to the BCM, but We are having a tough time figuring things out between the BCM, and ECM as far as the Pins go.
We have checked all the Wiring and Connectors/Pins under the Gas Tank, Neck, H-Bars, and around the Battery and Oil Tank.  And all Wiring going to the ECM, BCM, ABS, and Speedometer with less than positive results.  And the areas with the Modules behind the Oil Tank, in front of the Rear Fender/Guard.

I have the Factory Service, and Electrical Diagnostic Manuals for the Bike.  We are both dizzy from reading and re-reading them, and constantly looking at a Wiring Diagram.

Just wondering if any of You have been down this road before, and what the possible fix may be, if any. We are thinking maybe the BCM, or ECM.  But hope not.  Or a Bad Wire somewhere that We are not finding for whatever reason.  I am not grasping why the Centurian isn't seeing anything at all other then No Voltage.
Or should We just throw in the towel, load it on the Trailer, and let a Dealer deal with it, which We really don't want to do.  Trying to save a few bucks here, if possible.
Any help, hints, or suggestions will be appreciated.  Thanks in Advance.  Take Care.

[Hossamania]

Try disconnecting the FP3?

[Fugawee]

Yeah, that's gone.  You have to remove it to plug in the Centurian.

[pauly]

Just posted a stupid question so deleted it :-)
Have you checked continuity of all the canbus wires? PITA, however it would appear that there's an issue somewhere (if it's not ECU related).
Thanks
Pauly

[Fugawee]

I'm pretty stupid, overly qualified...so You should have left it there.

[Fugawee]

Yes, we have.  And Yes, it is a PITA.  The Canbus White/Red appears to be OK from testing.  The Canbus White/Black, We both feel that is what may be causing the problem...possibly being open somewhere.  But where is the question.  We are uncertain as to whether or not the Zero Voltage on that Wire at the ECM Connector is normal or not.
We are maybe going to look at another Bikes ECM to see what the Voltage is on that to maybe simplify this whole operation.  We tried using a Tone Wire Tracer on it, but the tone was spilling all over the place.  A waste of time.  At the end of the day, We were both pretty spent and fed up.  As well as Our eyes playing tricks.  We'll get back on it tomorrow.
Thanks for Your Suggestion.

[Tacocaster]

Jeeze Fug, that's nasty. When was the last time it ran and what's occurred since then leading up to this situation?

Recently had a System Relay go south and many of the same "supporting characters" were noted. That was on an '07 but hey, its super easy to bench test to see what ya get.

[Fugawee]

The last time it ran was in July.  The former Owner had an issue on the road and just had it brought to His house.  By My Buddy I might add.  It has sat since then...and now it's here.  The former Owner had it for more of a garage ornament.  Sunday rides...that's it.  Always serviced and what-not at a Dealer.  He says no more Motorcycles.
I don't think that there are any relays on this Bike.  If there are, I haven't seen any on the Bike or in the Manual.  And We both have looked at the Bikes Wiring and Manuals more times than We like.  But hey...We may have overlooked something.  This is making Our heads spin.
I wish that We had a Test Cable(s) that You could bridge on to the ECM, BCM, etc, for Testing Purposes.  The Dealers probably have something like that, but We don't.
Tomorrows another day...We'll see what happens.
Thanks for Your input.

[Coyote]

Checking for voltage is not the same as ohming the bus wires. You need to do the latter.

[Fugawee]

We have checked for Ohms and Voltages.  For some reason like I have mentioned the Canbus White/Black appears to be a problem.
But We could be wrong.  Wouldn't be the first time.

[Coyote]

What makes it appear to be a problem?

[Tacocaster]

Fug. Yes, a "breakout box" (you don't really need a physical "box") is an incredible tool for B-Y and trained Mechanics.

I made one out of an old (inline) Power Vision Unit for my '07 by simply cutting the "unit" away from the two connectors and re-splicing the connector's wires together with short pigtails attached for access (Numbered each by associated pin # and protected ends from grounding/shorting). Opened a whole new world of information to access and verify!

[pauly]

Haha fair enough - it was just about the voltage you said was on the canbus (2.5v)...I thought that was low but a little research had me better informed.
Another thing to be aware of is the canbus terminations. There's supposed to be a 120 ohm resistor at each end of the network, so the low to high resistance should read 60 ohms.

Thanks
Pauly

I'm pretty stupid, overly qualified...so You should have left it there.

[rigidthumper]

It's been a minute, but IIRC:
Can hi (R/W) & Can low (B/W) should hover around 2.5 VDC (Can hi should be just above 2.5V, Can low should be just below) if all is well and the system is quiet.  Once a request comes down the Can bus line (say, press the start switch/turn signal switch/hi beam/etc), Can hi will elevate to ~3.6V, Can low to ~1.4V. Once the request is done (release of the switch), system voltage should return to ~2.5V volts. Terminating resistors used, so you should always have between 50 Ω & 70 Ω between DLC pins 1 & 3. If not, unplug modules 1 @ a time, to see which unit (or wire) is affecting the system.
Can bus wiring short to power or short to ground will cause the U codes. Any shorted wire, or module, will affect the entire system, but, there is a crappy way to diag- 1 at a time, unplug every item plugged into the Can bus. Substitute a known good unit for any that appear to be causing the current codes. Replace any proven bad components, clear codes, and  evaluate. (If all else fails, trade for a Rolex )

[Fugawee]

Well, the Mystery is solved I do believe...I've been at this since 6 AM.  Lost sleep over this one.

There is a 3-way Canbus Heat Shrink splice way down low towards where the back of the Battery Tray is.
The Canbus White/Red, and the White/Black go to the BCM Connector, and up each side of the Frame under the Gas Tank going towards the H-bars.  I gave a Tug on that Splice earlier and out came the White/Black going to the BCM.  It pulled right out.  I temporarily pulled the Heat Shrink apart and twisted them all together.  Went thru the motions of starting it, and Bang Zoom...the Bike started, and all seems well.
I'll do a permanent fix later, or tomorrow, and clear the Codes; as well as put the Centurian on there and see what it says.  What a PITA!
I called My Buddy to tell Him the Good News, and an Executive Decision was made.  We have decided to take Our Bikes out for a ride along the Coast and treat Ourselves to some Greasy Lobster Rolls, and whatever else We may feel like.  Screw it.  It's a beautiful day here to get on out there.

Thanks Very Much to ALL of You for reading about the Issue, Your Input, and Advice.
Thanks Again,  Take Care.

[Hossamania]

Good catch, glad you got it!
I know exactly what you mean about losing sleep over that kind of stuff, it eats me up until solved.
Enjoy your ride, it's why we own them!

[Fugawee]

Thanks!  It ought to be good when I spring it on My Buddy that He's picking up todays tab.
That's the price that He's paying for My loss of sleep.  I will pay for my own gas though.