Road Glide banner

Why so many trouble codes?...hoy vay

6K views 14 replies 7 participants last post by  KSRIDER 
#1 ·
So, I got a 18' M8 scoot (RG)...I havent ridden it at all and theres only 2,000 original miles on it. My baby is a thing of beauty, shes all black but shes a bit sick.

So see if you can keep up:

I could use all your help.

This past winter I accidentally cracked the original throttle body on my air cleaner trying to upgrade to a Stage 1 air cleaner kit, so I did. i found a 17' M8 used throttle body with like less than 5000 miles on it, and I installed it, and never had a problem.
About 6 months ago, I wanted to take on a new project of trying to install a new Audio system, and I think the new issues began.

I took off my front fairing, my gas tank, I tried it but for the past 2 weeks at that time, the guy who I bought the front channel wiring kit from, turned out to be a real p%%%k!! Anyhow, at that moment I noticed, a check engine light came on over time that just wouldnt go away. and that opened up more issues, it almost seemed like the check engine light was interconnected with more issues over time.

Mind you, I still have that same check engine light, a solid red light right near the check engine light and a constant ABS light while Im riding.

For the past 2 months, Ive been getting trouble codes that when I clear them they always come back to the same ones. My ECM - U0141, U0121
My BCM - U0141, U0121
My RAD-U0001,U0003,U0185
My ABS-U0141, U0003
My SPD-U0156, U0158

So I am obviously going to do the obvious thing which is dump it at the dealer and hopefully have them put it on a scanner and figure out what is going on.

For all I know, I could have pinched a wire putting it all back together again.

SO: the issues that are present from these codes are.
A solid check engine light /red light which wont go away.
The radio doesnt work when I try and connect my blutooth from my phone (it has a speaker with the line through it)-(almost like its muted at the moment).

And after the bike warms up it idles like shit.
It goes from 1000-1200 then it drops to 600,then back up, then 400,then 300, and then it shuts off. (it stalls).
Especially while I'm riding and I'm at a red light, the same idling issue is persistent and present, as if nothing has changed, because it hasnt.

Now My mufflers are starting to pop, sounding like firecrackers, and its really annoying. (as opposed to before when it was just a smooth sounding pipe/muffler).

SO, obviously if your traveling along and a check engine light comes on, the ECM is usually signalling that theres a problem with a sensor, an open wire or a CAN/BUS line which is causing that check engine light to come on. And I've performed multiple DIAG test to retrieve these trouble codes. But, Ive come to a crossroad to just throw this bike in my local river because bad luck just follows me around.

And I have had it, I have so HAD IT!!!

Any idea what is happening?
Thanks
John
 
See less See more
#2 ·
John, sorry to hear that You are having such a problem with Your Glide.
Since You have listed all the Codes have You tried to reset the ECM?
If this doesn't correct the problem I would look at the CanBus system as all the Codes You listed are prefixed with U which I believe means they are a CanBus issue.
Here is a list of Harley Codes. https://dgcustomcycle.com/tech/harley-diagnostic-codes-04-present/
Sure hope You get it all figured out.
Mike U.
 
#8 ·
Check your grounds. Also there are ground studs on the frame in front of the battery called "clean grounds". Make sure nothing else gets grounded to those other than the black/green wires and they are secure. Otherwise I would reverse everything you did with the stereo, put it back to stock and start diagnosing from there. Good luck!
 
#10 ·
Let me ask you guys a question?

When you receive a trouble code, isn't it true that when your check engine light comes on and stays on when its usually received from the ECM of the vehicle that may state you have an open wire, or a bad sensor or a CAN BUS problem?, correct???

If the check engine light comes on and disappears, its usually a historical code that has come thru from the ECM?

So, here's my question each of the diagnostics have a specific area, when you do a sweep, after you turn the ignition to the on position.

What does CAN BUS mean, and how does that work?
 
#11 ·
John, this is the info on CAN BUS from The Good Old Interwebs.

CANBUS is an acronym for Controller Area Network Bus, originally developed by Bosch the same company that also developed the first O2 sensors.

CANBUS enables the manufacturer to greatly simplify the wiring harnesses for electronic components, which can reduce costs and improve the reliability of the system.
They don't have to run individual wires to carry discrete signals from each switch to the component to be controlled.

CANBUS is a message-based system, which we've been using in computer systems for decades.
Harley is finally catching up to this system.
It eliminates most of the point-to-point wiring because everything goes over a high-speed data bus.
Messages are sent from a switch component, to a cruise control component, telling it to do something instead of a signal being sent over a dedicated wire between the switch and the controlled device.

CANBUS vehicles have a LOT less wiring than older point-to-point discrete vehicles like pre-2011 Softails and pre-2014 Touring bikes.

Think of it as a kind of Local Area Network on your bike on which all of the components and switches "talk" over common wiring.

Hope this helps.
Mike U.
 
#13 ·
The bike may still be under the original warranty so take it to a dealer and have them check it out. I would think that with all the DTC's the bike has the dealer is your best bet. Also the dealer is the only place where the ABS code can be canceled because there isn't too many indy's that have the equipment to cancel ABS code.
 
  • Like
Reactions: RGKen
#14 ·
a) Some of those codes don't exist, you might want to have another look or hook it up to a scan tool.

b) The codes that are good, are all buss com codes.

So it almost has to go to the dealer to be diagnosed as there are several breakout boxes involved in the diagnostics, and the diagnostic ladder lists pin numbers in the boxes, not wire colors.

Now with that said, I've seen several threads already this year where people ran up big diagnostic bills and the issue was not found. Or was not fixed properly. But later turned out to be from ad-on electrical stuff. A set of spark coils on one and a set of Chicom tail lamps on another. So before you rape your wallet with dealer diagnostics, pull all of the aftermarket electrical stuff off of it and see what happens.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top