This Damn Fatboy!
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Outstanding HDF Member
Joined: Aug 2009
Posts: 2,594
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From: Moore, Oklahoma
This Damn Fatboy!
2013 Fatboy Lo with 5188 miles.....
No speedo needle after a short ride. Throwing code b2173.
Checked all of the wiring I have messed with since I changed the bars and tail lights last year. All good.
Changed the BCM and Speed Sensor. Still screwed.
The red trouble light will be intermittent while sitting still or on the road.
Bike will idle so low at the stop lights that it dies.
Fires right back up and runs fine (except for no speedo-needle) until I come to the next light..... low idle.... dies.
Harley techs are stumped........
AAAnndd they want $110.00 an hour to put it on the Digital Technician...
PLEASE HELP......
No speedo needle after a short ride. Throwing code b2173.
Checked all of the wiring I have messed with since I changed the bars and tail lights last year. All good.
Changed the BCM and Speed Sensor. Still screwed.
The red trouble light will be intermittent while sitting still or on the road.
Bike will idle so low at the stop lights that it dies.
Fires right back up and runs fine (except for no speedo-needle) until I come to the next light..... low idle.... dies.
Harley techs are stumped........
AAAnndd they want $110.00 an hour to put it on the Digital Technician...
PLEASE HELP......
Seasoned HDF Member
Joined: Jul 2009
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From: Virginia
Outstanding HDF Member
Joined: Feb 2015
Posts: 2,414
Likes: 433
From: Arkansas
Are you first owner? Has the fuel mapping/ idle been adjusted via flashing of the computer or is there a FP or PC installed? You may have 2 issues one is if there is a FP or PC installed that may be causing the low idle condition and 2 the speedo may be failing causing no needle indications. If flashed via PowerVison or SEST you may need to reflash back to stock. Check your wiring going to the siren, maybe chaffing on the harness. Who knows maybe chaffing is causing all of the issues, check the harness on the backbone. Good Luck!
HDF Community Team
Joined: Mar 2005
Posts: 1,865
Likes: 524
From: The 1980's
2013 Fatboy Lo with 5188 miles.....
No speedo needle after a short ride. Throwing code b2173.
Checked all of the wiring I have messed with since I changed the bars and tail lights last year. All good.
Changed the BCM and Speed Sensor. Still screwed.
The red trouble light will be intermittent while sitting still or on the road.
Bike will idle so low at the stop lights that it dies.
Fires right back up and runs fine (except for no speedo-needle) until I come to the next light..... low idle.... dies.
Harley techs are stumped........
AAAnndd they want $110.00 an hour to put it on the Digital Technician...
PLEASE HELP......
No speedo needle after a short ride. Throwing code b2173.
Checked all of the wiring I have messed with since I changed the bars and tail lights last year. All good.
Changed the BCM and Speed Sensor. Still screwed.
The red trouble light will be intermittent while sitting still or on the road.
Bike will idle so low at the stop lights that it dies.
Fires right back up and runs fine (except for no speedo-needle) until I come to the next light..... low idle.... dies.
Harley techs are stumped........
AAAnndd they want $110.00 an hour to put it on the Digital Technician...
PLEASE HELP......
I went down that road with a 2003 Cadillac last year. Should have just taken it to my local shop guys first instead of throwing money at ebay parts that were junk to begin with in the attempt to fix it myself.
Last edited by 2goldens; Feb 19, 2017 at 06:13 AM.
Tourer
Joined: Dec 2015
Posts: 338
Likes: 82
From: England
Your low idle and cutting out at lights is due to your Idle Air Control motor's position relying on speed imput to maintain correct idle.
Your speedo needle not moving would suggest that IAC motor is not getting the information it needs to position itself correctly.
The Vehicle Speed Sensor sends imputs to the ECM which then sends a Canbus message to the speedometer telling it where the needle should be.
Your VSS shares a 5 volt power supply on the red/white wire with other sensors on the bike. You should confirm that the VSS is getting that 5 volts and that the wire isn't damaged to either the Vss or to any of the other sensors that share that wire. The MAP, TPS and Jiffy stand sensor if you have one.
You should also check the ground wire Green/black for good continuity to ground. Also that it isn't broken or damaged along its length to the VSS.
You can also check the Light green/ yellow wire which is the imput wire going back to the ECM which is the wire the ECM uses to interperete what the speed should be.
Disconnect the ECM block connector and the VSS connector and check for continuity along this wire and that it isn't going to ground.
When you access speedo diagnostics, just prior to getting to the code portion, the speedo performs a "wow" test where it lights up and the speedo needle should perform a sweep....does the needle sweep at this point?
The BCM doesn't really play a part in the speed signal imput.
The speedo sensor can fail but it sounds like having changed it, that it isn't at fault so check that wiring from the speedo sensor, the power, the earth and the signal is a good place to start looking.
Your speedo needle not moving would suggest that IAC motor is not getting the information it needs to position itself correctly.
The Vehicle Speed Sensor sends imputs to the ECM which then sends a Canbus message to the speedometer telling it where the needle should be.
Your VSS shares a 5 volt power supply on the red/white wire with other sensors on the bike. You should confirm that the VSS is getting that 5 volts and that the wire isn't damaged to either the Vss or to any of the other sensors that share that wire. The MAP, TPS and Jiffy stand sensor if you have one.
You should also check the ground wire Green/black for good continuity to ground. Also that it isn't broken or damaged along its length to the VSS.
You can also check the Light green/ yellow wire which is the imput wire going back to the ECM which is the wire the ECM uses to interperete what the speed should be.
Disconnect the ECM block connector and the VSS connector and check for continuity along this wire and that it isn't going to ground.
When you access speedo diagnostics, just prior to getting to the code portion, the speedo performs a "wow" test where it lights up and the speedo needle should perform a sweep....does the needle sweep at this point?
The BCM doesn't really play a part in the speed signal imput.
The speedo sensor can fail but it sounds like having changed it, that it isn't at fault so check that wiring from the speedo sensor, the power, the earth and the signal is a good place to start looking.
Last edited by j_bee; Feb 19, 2017 at 05:55 PM.
Thread Starter
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Outstanding HDF Member
Joined: Aug 2009
Posts: 2,594
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From: Moore, Oklahoma
Well, I did the research for the other folks who've had a similar issue, and came to the conclusions that the Speed sensor and the BCM were crap. I changed the SS first, no dice. I ordered a BCM (correct part number) from ebay (Because I am a cheap son of a bitch that hates buying HD parts from the dealer). It turned out to have the exact same problem, which is why it was sold in the first place I am sure.
I dropped the bike off last week and had them run the diagnostic and decided to have them put the NEW 281.00 BCM in..... Soooo, $420.00 later..... I am picking my bike up on Saturday.
End result,
70.00 for speed sensor - unnecessary
55.00 for eBay BCM - Stupid and unnecessary
110.00 for HD diagnostic - Grudgingly necessary
281.00 for Dealer BCM - FUUUUCK!!
blew 125.00 because I tried to be cheap and stupid.
Thank you for everyone who responded and helped. BTW, this isn't my first HD and I have done all work on all my bikes myself. So, this was a new experience and one I won't forget........
I dropped the bike off last week and had them run the diagnostic and decided to have them put the NEW 281.00 BCM in..... Soooo, $420.00 later..... I am picking my bike up on Saturday.
End result,
70.00 for speed sensor - unnecessary
55.00 for eBay BCM - Stupid and unnecessary
110.00 for HD diagnostic - Grudgingly necessary
281.00 for Dealer BCM - FUUUUCK!!
blew 125.00 because I tried to be cheap and stupid.
Thank you for everyone who responded and helped. BTW, this isn't my first HD and I have done all work on all my bikes myself. So, this was a new experience and one I won't forget........
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Thread Starter
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Outstanding HDF Member
Joined: Aug 2009
Posts: 2,594
Likes: 4
From: Moore, Oklahoma
Ok, so UPDATE! Picked the bike up on that Saturday, drove it off the lot and still had the same problem. Took it back. There was a three wire plug that was plugged into the wrong spot on the left side..... I know I didn't do that. So, after taking the bike right back to the dealer, the lead tech found the problem and swapped the wires. He said it was probably like that from the factory. It lasted as long as it did, and then blew the BCM. It popped the new BCM too, so until he found that wiring F-up, it wouldn't continued to be a problem. Anyway, Bike is fixed and runs great.
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