how do you fix bcm code b2121,
Stage III
Joined: Mar 2019
Posts: 3
Likes: 0
From: lebanon
Thanks for your reply dear,, but 2014 model have no starter relay ,, i think it is in the bcm now,, what do you mean by system relays??
Stage I
Joined: Jul 2019
Posts: 1
Likes: 0
From: Australia
Ok so I have the same issue on my 2015 FXDWG, I had the ground cable break at the battery terminal while riding. Fixed that and then no starting and the code b2121 showing. Checked all the wiring everything. The issue is in the BCM starter circuit. I was told that as the cable broke this caused power fluctuations that damaged the BCM. A new BCM is required.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
Stage II
Joined: May 2022
Posts: 2
Likes: 0
From: Usa
Quick fix
quick fix. Disconnect the inline fuse connected to the battery. It worked for my 2020 street bob
Stage III
Joined: May 2022
Posts: 3
Likes: 1
From: Minnesota
Ok so I have the same issue on my 2015 FXDWG, I had the ground cable break at the battery terminal while riding. Fixed that and then no starting and the code b2121 showing. Checked all the wiring everything. The issue is in the BCM starter circuit. I was told that as the cable broke this caused power fluctuations that damaged the BCM. A new BCM is required.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
Did you ever get this resolved? Same issue on 13 slim after trailering 250 mikes with loose battery cables. I suspected BCM although everything else works off the bcm, lights, horn, etc.. and I can still communicate and pull codes from the BCM
Stage III
Joined: Nov 2015
Posts: 3
Likes: 0
From: Egypt
Hello, same issue here XLN 2014
The thing is, if you push-start the bike it WILL RUN.
This is my friend's bike, mine is an 2009 Iron and when I had this issue I just replaced the starter relay. Makes me wonder, why the **** did they do that ?
Push your bike (get someone to push you) release the clutch on second gear (experience needed), and it will start.
The problem is with the freakin BCM that cannot understand what happened after the negative terminal went loose/cut-off.
Please let me know if you resolved without changing BCM.
Cheers
The thing is, if you push-start the bike it WILL RUN.
This is my friend's bike, mine is an 2009 Iron and when I had this issue I just replaced the starter relay. Makes me wonder, why the **** did they do that ?
Push your bike (get someone to push you) release the clutch on second gear (experience needed), and it will start.
The problem is with the freakin BCM that cannot understand what happened after the negative terminal went loose/cut-off.
Please let me know if you resolved without changing BCM.
Cheers
Stage I
Joined: Jul 2024
Posts: 1
Likes: 0
From: Long beach
Ok so I have the same issue on my 2015 FXDWG, I had the ground cable break at the battery terminal while riding. Fixed that and then no starting and the code b2121 showing. Checked all the wiring everything. The issue is in the BCM starter circuit. I was told that as the cable broke this caused power fluctuations that damaged the BCM. A new BCM is required.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
In the meantime I have connected a relay and momentary switch (with a fuse) to the starter solenoid and the battery. Basically bypassed the BCM for starting, works perfectly. If you wanted you could even use the original starter switch but I chose to hide my new starter switch out of view.
How did you wire the switch??
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