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Motorbike
| Posted on Sunday, August 07, 2022 - 07:00 pm: |
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I am getting a code 15 (IAT Sensor voltage High/Low) on my 2008 XB12XT with 32000 miles. This started a few days ago when idling through Sturgis,SD on a 101 degree day. The CEL would be on for a while then off for a while. It finally got to a point where it is on most of the time now. When I got home, I checked the IAT Sensor and it was coated with oil. I cleaned it with Throttle Body Cleaner so it is bone dry. The CEL is still on, same code 15. I have no way to clear it. The bike does not run well since this all started, popping back through the intake etc. My question is, will the code that is set in the ECM cause the bike to run this bad, even if the IAT is now okay? Should I try replacing the IAT Sensor? Any ideas would be greatly appreciated. Thanks! PS Does anyone have the part number for this IAT Sensor? Does it cross over to any Ford part numbers? |
Lew360
| Posted on Sunday, August 07, 2022 - 07:33 pm: |
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Standard Motor Products AX31 works. I just replaced mine with that from Amazon. Don't know the exact Ford part number but it is a Ford part. |
Motorbike
| Posted on Sunday, August 07, 2022 - 08:59 pm: |
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Thanks Lew. Were you having the code 15 issues as I am? Did that fix your bike? |
Hughlysses
| Posted on Monday, August 08, 2022 - 07:48 am: |
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Side note- if your IAT sensor is coated with oil, you may be carrying your engine oil level too high. High oil level will result in excess oil getting blown out of the breather hoses into the airbox. The 2008-up bikes can be tricky to accurately read. The best method a lot of us have found is to check the oil with the bike on the side stand with the engine hot and idling. You want the level to be no higher than the middle of the X’s (operating range) on the dipstick. Any higher than this and the engine blows the excess into the airbox, which can coat the IAT causing problems. |
Tootal
| Posted on Monday, August 08, 2022 - 10:12 am: |
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Almost. The engine can be idling when you pull the dipstick out but then you must shut it off and then put the stick back in to check it and it must be screwed in. If you check it while it's running it will always be at the 2nd X because the return flow hits the dipstick there. I was checking my oil this way and couldn't figure out why my oil pressure light was coming on at idle. I thought my oil filter was clogged up or something. Finally I checked it with the engine off and there was nothing on the dipstick!! |
Hughlysses
| Posted on Monday, August 08, 2022 - 10:20 am: |
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Greg- Apparently on the 2008 up models, the oil is more prone to leaking from the swingarm back into the crankcase when you shut the engine down. If you don’t check it immediately after shutdown, it’ll tend to read low. I’ve had good luck with the method I outlined, but it seems like it would suffer from the same issue you mention. |
Tootal
| Posted on Monday, August 08, 2022 - 10:47 am: |
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That's right. I check mine hot and pull the dipstick while it's running then shut it off and immediately take a reading. After I saw I had no oil on the dipstick I fired it up and took another reading and it was right on the Dos XX. Lesson learned. Stopped by a gas station and grabbed some diesel oil and filled it to the Dos XX. Light stayed out. And here I thought I wasn't using any oil!! |
Lew360
| Posted on Tuesday, August 09, 2022 - 01:28 pm: |
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Never had that code. I was having a stalling at cold idle and lean after fire until it got warmed up. It hasn't completely curred the problem I think my tune is lean at idle until warm. |
Motorbike
| Posted on Thursday, August 11, 2022 - 06:23 pm: |
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Thanks for the replies. "Side note- if your IAT sensor is coated with oil, you may be carrying your engine oil level too high. High oil level will result in excess oil getting blown out of the breather hoses into the airbox." Hugh, I wondered about the oil level as well but I checked it a few ways and it seems okay, as near as I can tell. Also, when I last changed oil, I drained it hot and left it overnight. Refilled with exactly 2.5 Qts and have not added any since then. The Code 15 showed up about 1500 miles after the oil change. I called a HD dealer today and he said the IAT HD Part# P0138.K is not available at any dealership. I guess I will order the SMP AX31 as LEW360 suggested. I know it would be less expensive anyway. If I replace the IAT, how can I tell if the problem is fixed? I have no way to clear the code. (Disconnecting the battery for an hour didn't work) It seems there are other issues as well and I am wondering if these might clear up after IAT replacement if the original is in fact defective? I installed an EBR ECM several years ago which has always turned the fan on above 15 MPH and it doesn't seem to do that right now. Also, If I start the bike and let it idle, the fan used to turn on if the engine got a little warm. Doesn't seem to do that anymore either. I have heard the fan a couple of times though so I know it can run, just not sure when it should. All of this crap started when the code 15 showed up. Prior to that, this bike was running perfectly. Any recommendations? Should I just start with a new IAT Sensor? I wonder if the engine temperature sensor is bad but there is no code other than the 15. |
Griffmeister
| Posted on Friday, August 12, 2022 - 11:43 am: |
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There are some simple tests you can do to help confirm the source of the problem. The IAC is a thermistor so you can read resistance across its terminals. At normal temperatures between 60 and 90 degrees f the resistance should be between 6816 and 3314 ohms. On the ECM side of the connector you should have 4.7 to 5.3 VDC with the key on. If either of these is out of range then you may be closer to the problem. Another note with things that vibrate, over time as terminals age, the clamping force in the female terminals can get weak where you will start to get intermittent connections as things shake around. Also, wires can start to break behind the terminals as many of us have experienced on the steering head. Just saying that the problem may not always be obvious. For the record, you can clear a CEL with 50 start/run cycles. But who the hell wants to do that especially if the code is still active? |
Motorbike
| Posted on Friday, August 12, 2022 - 03:15 pm: |
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Thanks Griff, I will check the ohms and voltage. Is the voltage measured from ground to one of the wires in the connector or is it from one wire to the other in the connector? Is one of the wires in the connector actually a ground anyway? If I replace the IAT and it fixes the issues, will the CEL turn off in the dash and only have the code stored in the ECM? Or will it only shut off the CEL after 50 complete cycles? |
Griffmeister
| Posted on Friday, August 12, 2022 - 06:18 pm: |
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Yeah, that’s typical for a control module. One side is ground (through the controller) and the other side is power. So, if you unplug the IAT you should be able to read across the two leads. If you don’t read voltage, then you can go to chassis ground and check again just in case there is a ground wire problem. This is where a breakout box comes in real handy, but boy are they expensive, if you could even find one anymore. As far as the CEL, the code will be stored in memory for the 50 cycles. I’m pretty sure the light will go out if the problem is fixed. Don’t quote me on that though. |
Motorbike
| Posted on Saturday, August 13, 2022 - 05:50 pm: |
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I think I may have figured out the Code 15 IAT issue. I checked for 5 volts at the connector that plugs to the IAT Sensor. Nothing. I then checked for continuity from the green/yellow wire at the IAT connector to the pin 14 of the gray ECM connector. No continuity, so I knew the wire was open/broken. I also checked the continuity of the black wire to pin 27 and it was good. (Thanks Griff!) I then untaped the harness a bit and found the green/yellow wire was broken right next to the IAT connector. I tried to remove the terminal from the connector so I could repair this but was unable to get it to release. I even broke the plastic connector a bit. Does anyone have any idea where I could get a new connector like this with short pigtails so I could just splice it into the original harness? If I cannot find one, I may have to figure out what type of automotive applications the IAT sensor has and scour the salvage yards to see if I can find a vehicle that I can clip the connector from and splice it in. Is it just my bike or have any of you noticed that all of the wires on these bikes are absolutely as short as they could possibly be with no slack whatsoever? Why would anyone who designs a bike that vibrates not allow a tiny bit of extra wire to allow for a little flexing? I really doubt I will find this exact connector new but that would be my first choice. Any ideas? Thank you! Update: I did a little research and found I could buy the connector with pigtails at a local auto parts store. It is a Standard Ignition Products #S1080. $55.99. Kinda steep but I have no choice I guess. I can have it shipped from another online auto part source but would have to wait and it would still be $34.
(Message edited by Motorbike on August 13, 2022) |
Hughlysses
| Posted on Saturday, August 13, 2022 - 10:01 pm: |
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A lot of these connectors can be “unpinned”. You insert a pointy object in the correct location and the metal terminal that the wire is connected to will come out of the plug. If you get that out, you can probably bend the terminal open, remove the old wire and add a length of new wire. IIRC, the shop manual has a section showing how to unpin the various connectors. Another thought would be to find one on a car in a junkyard. That seems like the kind of thing they’d sell,you for a couple of bucks. |
Motorbike
| Posted on Sunday, August 14, 2022 - 08:29 am: |
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I tried the method shown in the shop manual but may have been doing it wrong anyway. I just couldn't get it to release and when I tried harder, it broke the plastic. Me and my big hands! Oh well, I want to get it done today so I'll probably just buy the new part and work a little OT this week to pay for it. None of the junkyards are open today. (I could probably find one on my wife's Ford but I would just end up having to fix that too, along with my marriage.) Thank you all for your help. I will post back after I try the new connector to let you know if this is fixed. |
Motorbike
| Posted on Sunday, August 14, 2022 - 06:52 pm: |
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I replaced the IAT connector today with a Standard Ignition #S1080 Connector. I put it all back together and fired it up. Seemed to run a little rough at first and then smoothed out a little as it warmed up. I shut it off after it warmed up and then did a TPS reset. Fired it up and went for a short test ride, 14 miles. Seems to run great, just like before. Also, no CEL. I didn't check to see if the Code 15 was stored in the ECM, don't really need to know. I'm hoping the initial rough running was just due to the ECM relearning some of the parameters. Also, the fan seems to operate as normal again, comes on at exactly 15 MPH. |
Hughlysses
| Posted on Sunday, August 14, 2022 - 07:16 pm: |
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Whisperstealth
| Posted on Sunday, August 14, 2022 - 07:53 pm: |
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That's Great! Congratulations on the successful repair! Happy riding! |
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