U0121
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Road Captain
Joined: Mar 2017
Posts: 537
Likes: 86
From: FL
U0121
I am hoping I can get some help here. I bought my wife's 2015 Street Glide Special used and not too long after it we were riding and the ABS and check engine lights came on. We stopped, turned the bike off and restarted it. The lights were now off. This happened a couple time in the 4000 miles she has ridden it. Fast forward a couple months and I changed out the bars for 10"ers. After a couple rides the lights were more intermittent and I lost the clutch side controls. I took it back apart and I found a recessed pin on the HD extension cable I used for the bar install. After I got it all back together everything is working great (controls work and no light right now) I went through and cleared all the codes. Right now I have code U0121 hard set on the BCM and RAD circuit. Dose anyone have ides on what to look for next to fix this U0121 code issue I am having now?
Thank you in advance for any help you can provide.
Thank you in advance for any help you can provide.
Thread Starter
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Road Captain
Joined: Mar 2017
Posts: 537
Likes: 86
From: FL
It comes on intermittently. But typicality turning off the bike and restarting clears it. Anyone have any ideas of where I can look for loose connections or broken wires?
Thank you,
Marc
Thank you,
Marc
1st Gear
Joined: Oct 2024
Posts: 5
Likes: 1
persistent U0121 code
This is an old thread and I hope you are still on the road. I am facing a very similar issue (U0121 on BCM and SPDO) with my Fat Bob (2014). Checked all the wires and connectors but found nothing wrong. I searched the internet and found almost nothing, apart from this thread.
Were you able at the time to resolve this? If so, do you remember what the cause was?
Thanks in advance!
Steven
Seasoned HDF Member
Joined: Sep 2009
Posts: 17,145
Likes: 6,168
From: SE Michigan
Hi Marc
This is an old thread and I hope you are still on the road. I am facing a very similar issue (U0121 on BCM and SPDO) with my Fat Bob (2014). Checked all the wires and connectors but found nothing wrong. I searched the internet and found almost nothing, apart from this thread.
Were you able at the time to resolve this? If so, do you remember what the cause was?
Thanks in advance!
Steven
This is an old thread and I hope you are still on the road. I am facing a very similar issue (U0121 on BCM and SPDO) with my Fat Bob (2014). Checked all the wires and connectors but found nothing wrong. I searched the internet and found almost nothing, apart from this thread.
Were you able at the time to resolve this? If so, do you remember what the cause was?
Thanks in advance!
Steven
Stellar HDF Member
Joined: Aug 2019
Posts: 3,121
Likes: 1,906
From: Unreconstructed
Hi Marc
This is an old thread and I hope you are still on the road. I am facing a very similar issue (U0121 on BCM and SPDO) with my Fat Bob (2014). Checked all the wires and connectors but found nothing wrong. I searched the internet and found almost nothing, apart from this thread.
Were you able at the time to resolve this? If so, do you remember what the cause was?
Thanks in advance!
Steven
This is an old thread and I hope you are still on the road. I am facing a very similar issue (U0121 on BCM and SPDO) with my Fat Bob (2014). Checked all the wires and connectors but found nothing wrong. I searched the internet and found almost nothing, apart from this thread.
Were you able at the time to resolve this? If so, do you remember what the cause was?
Thanks in advance!
Steven
1st Gear
Joined: Oct 2024
Posts: 5
Likes: 1
I cleared the codes several times already, but they keep coming back. Unfortunately, this is rather unpredictable. I made a 400 km trip in the week-end and no codes at all. Yesterday, after riding to work and back (40 km total), it had produced them again. The battery should be fine, I keep it charged with a trickle charger and starting was never a problem.
I am currently disassembling the battery bay and ECM bay again to check everything once more and clean all connectors with contact spray. If I don't find anything suspicious, I plan to start it and manually move the wires to simulate movement/shocks on the road. See if I can trigger the code generation that way. After that I will be out of inspiration :-(. Any ideas are very welcome :-).
I am currently disassembling the battery bay and ECM bay again to check everything once more and clean all connectors with contact spray. If I don't find anything suspicious, I plan to start it and manually move the wires to simulate movement/shocks on the road. See if I can trigger the code generation that way. After that I will be out of inspiration :-(. Any ideas are very welcome :-).
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Stellar HDF Member
Joined: Aug 2019
Posts: 3,121
Likes: 1,906
From: Unreconstructed
Does the bike have ABS? My guess is that your connector issues are going to be up in the spine of the bike where the hand controls meet the harness.
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1st Gear
Joined: Oct 2024
Posts: 5
Likes: 1
Hi Snake_eyes, yes it has ABS. You mean the location right behind the steering head, under the tank?
There are several connectors there indeed. I checked them before and saw nothing suspicious at that time, but I didn't unwrap the cable harness or so.
Do you have a specific reason to suspect that location? If you think the cause is more likely there, I will check it again.
There are several connectors there indeed. I checked them before and saw nothing suspicious at that time, but I didn't unwrap the cable harness or so.
Do you have a specific reason to suspect that location? If you think the cause is more likely there, I will check it again.
Stellar HDF Member
Joined: Aug 2019
Posts: 3,121
Likes: 1,906
From: Unreconstructed
Hi Snake_eyes, yes it has ABS. You mean the location right behind the steering head, under the tank?
There are several connectors there indeed. I checked them before and saw nothing suspicious at that time, but I didn't unwrap the cable harness or so.
Do you have a specific reason to suspect that location? If you think the cause is more likely there, I will check it again.
There are several connectors there indeed. I checked them before and saw nothing suspicious at that time, but I didn't unwrap the cable harness or so.
Do you have a specific reason to suspect that location? If you think the cause is more likely there, I will check it again.