limp mode/check engine
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Tourer
Joined: Apr 2014
Posts: 267
Likes: 19
From: south
limp mode/check engine
Heading back home after 754 trouble free, beautiful miles in Maggie Valley and the Blue Ridge, I experienced my first ever check engine and the resulting limp mode on my 2010 Ultra. We were on I-40, 75 MPH, flat, no grade and suddenly just lost power. Noticed the check engine light, and hit the right lane as speed dropped. Luckily we were near an exit, and after getting off the interstate and finding a place to pull up, I shut the bike down. Me and wifey sat for a second, and I attempted to start her back up, which she did with no problem. Checked for codes, got a po134, front O2 sensor open/not responding. Bike ran well, no problem, to a gas station just down the road. I gassed up, half a tank maybe, and we started up to make the last 150 odd miles home. Had zero problems, started out kinda slow, 55/60 but gradually worked back up to 70/75 and didn't have the slightest sign of a problem, bike ran great and no more check engine light. I cleared the code when I got home, so far it hasn't reappeared. What should I do now, is there something that needs immediate attention? Could a freak occurrence throw a code and reset or disappear? thanks in advance for any suggestions.
Cruiser
Joined: Dec 2012
Posts: 106
Likes: 39
From: Vineland Ontario Canada
Well, this may or may not be perplexing issue but I certainly hope not. If it were me I would start by inspecting as much of the 02 wiring as possible for opens or short to ground at some point. If nothing, then switch the o2 sensors front to rear which I suspect are the same, then ride it around for a while not too far from home and see what transpires.
Mike
Mike
Advanced
Joined: Jul 2017
Posts: 78
Likes: 29
From: Memphis, TN
Check the TBW electrical connection on the throttle body, right behind the air cleaner. The pins in that connection are known to fret. Happened to me last year on my '09, had them replace the pins and all was good.
Elite HDF Member
Joined: Jun 2011
Posts: 3,832
Likes: 127
From: Coastal Carolina
I had a similar circumstance with a different cod--P0118--which is an open/high engine temperature sensor. I checked wires and every condition that my electrical diagnostic manual told me could cause a high heat reading on the sensor. I continued to have occasional stutters and power losses intermittently. Finally I just decided to replace the sensor itself (a $38 part and a 10 minute swap). And now the bike runs perfectly again. I have no idea why a sensor goes bad (and the old one looked the same as the new one, no outward sign that would indicate failure). I do have lots of miles on the bike (just under 57,000) so maybe they just wear out.
But if your O2 sensor is as cheap and easy to replace (I didn't pull the manual to check) you might think of trying that if you get the check engine light again.
But if your O2 sensor is as cheap and easy to replace (I didn't pull the manual to check) you might think of trying that if you get the check engine light again.
This is probably your problem, happened to me and many others. I believe they changed this to a rubber boot in 2011 or 2012, Pull off, clean both connections really well with electrical contact cleaner, compressed air till dry and connect again. I do mine about 2-3 times a riding season. That limp mode blows when that happens, be lucky you both got home! Ride safe!!
Seasoned HDF Member
Joined: May 2012
Posts: 32,934
Likes: 36,027
From: Carlsbad, CA
This is probably your problem, happened to me and many others. I believe they changed this to a rubber boot in 2011 or 2012, Pull off, clean both connections really well with electrical contact cleaner, compressed air till dry and connect again. I do mine about 2-3 times a riding season. That limp mode blows when that happens, be lucky you both got home! Ride safe!!
Club Member
Joined: Sep 2006
Posts: 1,003
Likes: 69
From: Granite Falls, NC
That happened to me also. I pulled the connector apart on the throttle body and sprayed it out with some 02 sensor cleaner and put dielectric grease on it and never had any more problems. May want to check the ECM connector under the seat. On long rides like that we like to wiggle our butts and could have pulled connector loose.
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Road Warrior
Joined: Nov 2007
Posts: 1,800
Likes: 307
From: Houston, Texas
The fretting problem is not with the pin to pin connections in the connector. It's where the wire is connected to the pin on the plug. Soldering the wire to the pins on the plug takes care of that. It can definitely be an issue but wouldn't throw a code for an 02 sensor.
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!
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The fretting problem is not with the pin to pin connections in the connector. It's where the wire is connected to the pin on the plug. Soldering the wire to the pins on the plug takes care of that. It can definitely be an issue but wouldn't throw a code for an 02 sensor.
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!
http://www.cdcorrosion.com/mode_corr...n_fretting.htm
This is the best layman terms for fretting corrosion.
https://www.hdforums.com/forum/exhau...questions.html
O2 sensor info, found on forum. Ride safe!!
Thread Starter
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Tourer
Joined: Apr 2014
Posts: 267
Likes: 19
From: south
The fretting problem is not with the pin to pin connections in the connector. It's where the wire is connected to the pin on the plug. Soldering the wire to the pins on the plug takes care of that. It can definitely be an issue but wouldn't throw a code for an 02 sensor.
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!
As previously mentioned, I'd look at the wires and connection on the sensor and consider simply replacing it. They do fail over time and are not hard to swap and not outrageously priced. I recently changed both on mine.
Some one please correct me if I am wrong but when an O2 sensor fails the ECM quits reading it and uses a single default reading. That could account for the performance change. I don't think that would cause a true limp mode to occur. You're just now in closed loop tuning on a fixed setting and not open loop based on the sensor reading. If the light cleared, your back to normal tuning off the sensor.
Good luck!