Check engine light

Good day to all,

2008 XB12XT 26,500 miles(give or take).

I have got the following codes that came up using the Buelltooth and ECMdroid app.
Code 21 - AMC stuck open
Code 0 - Baro short to supply voltage/broken wire

CEL came on briefly a while ago and went off again. It would flash once every now and then and then go off until the next ride. Did this on a few rides and now is permanently on.

Motorcycle rides as it should. No misfires, stutters, hickups, loss of power or anything noticeable except that the CEL is on. All the reading and info gathered from the forums suggests a CEL is always accompanied by some other symptom which I do not hear or feel.

I have checked connections, fuses and relays, oil level (but not primary oil level), the fan runs like it always has, I've checked the servo to see if any of the gears are damaged and I also checked the cable which feels smooth when pulled and then there's an audible click coming from the exhaust.

So one thing thing that does completely get me is the Code 0, as when I search the list of codes it doesn't exist. Also the motorcycle doesn't have a Barometer. Or am I missing something here?

Any help would be appreciated.

Cheers
Andrew

You should be able to use the same program (active tests) to cycle the exhaust valve, use a flashlight to look at the muffler end of the cable to see the whole system work.

Ya you're right, no baro on yours. Even if it was modified to have one (Rev-Mo) it would be able to throw any code.

Cooter said:

You should be able to use the same program (active tests) to cycle the exhaust valve, use a flashlight to look at the muffler end of the cable to see the whole system work.

Ya you're right, no baro on yours. Even if it was modified to have one (Rev-Mo) it would be able to throw any code.

Click to expand...

I would use ECMDroid active tests function to test the action of the exhaust valve to make sure its working at the servo AND the muffler. You may need to use a flashlight to see the muffler valve move.

The XB's never used a barometric pressure sensor, but a loose battery cable, flakey connections, or a failing battery can cause the ECM to throw weird codes.

Simultaneous fault codes #'s 0 and 21 are specific to the ECM seeing resistance values produced from the IEV actuator assembly that it doesn't like along with having been fiddled with and not linked to an operational IEV system. Resistance can be produced from the actuator...the cable...the IEV muffler valve. Simple ways to test and correct this, then clear the active and historical codes.

So I did an active test on the exhaust valve and I do not see any movement at the muffler or hear any noise from the servo actuator.

I did other tests like fan and fuel pump to see that the tests actually work and those all are fine.

I forgot to mention that I did check the connections at the battery and they had a bit of corrosion that I took care of it.

I am guessing the servo unit is toast? What are my next steps? Could I bypass the system like I've seen mentioned in other threads or will it just be best to get a new unit? I don't want to compromise on performance and take short cuts that would cost me in the long run.

Thank you guys for the help so far. I appreciate it and this is a learning curve for me.

When my exhaust valve actuator went bad i did the dorman 911-912 mod. It takes a little work but saves some money and works well if you want to keep the system operable.

Steps to isolate, confirm and resolve this problem are below for you. 2008 SPECIFICALLY. You're welcome.

1-CHECK fuse box. 2008 IEV system fused with BRAKE/HORN 10A fuse. Check fuse.
2-Access your ECM again. Check for enable EEPROM burning. Check the optimized burning box. Then check that the IEV system has NOT been disabled.
3-CHECK in this exact order after confirming 10A fuse is OK:
DO NOT START MOTOR----KEY OFF---TWIST THROTTLE TO FULL WIDE OPEN---RED KILL SWITCH TO ON---TURN KEY TO ON-
On 2008 model you should simultaneously hear coil test firing both spark plugs as well as IEV actuator opening the muffler valve ONE TIME.

If all the above fails then follow Starman's advice and go the Dorman 911-912 route or good used 2004-2009 IEV actuator from Ebay, if inexpensive. Dorman, with exception of minor mod to the bell-crank cable operator, is plug-and-play and top quality internals. Plenty of links available on how to perform this swap.

Lube muffler valve with old-school exhaust manifold heat riser valve lube....lube cable...confirm both working smoothly.
Clean all fault codes.

Thank you Barrett for the step by step guide.

I did all of the above. For good measure I changed the fuse after checking it. The old one was replaced a while ago but to be 100% sure I checked them all again and replaced it.

After doing all of the steps I did not find any change so I will be looking into either going the Dorman route or if I could find a IEV actuator I might just get it.

Currently the cable and muffler valve feels smooth when actuated manually. I'd make sure that if I install any new parts to lube it all up and clear codes.

My pleasure Andrew and well done. The OEM factory IEV actuator was slightly upgraded and given a new part # Fall of 2007 but upgrades were minimal. The Dorman part # is Ford application for some gizmo on Ford intake tract runners, as I recall. It is a very nice piece for not much money and big improvement over Buell piece...nice easy evening project...much less money than good used or new Buell part. I'd go the Dorman route. See link below for all that you'll need and pics.

https://www.buellxb.com/forum/showthread.php?52942-Disabled-exhaust-valve-actuator


And here...

https://www.ebay.com/itm/2549047002...dA9R8bHKM60g6aeeKi19XqogVk1WhQ68aAnQeEALw_wcB


and here....
https://www.amazon.com/Dorman-911-912-Intake-Manifold-Solenoid/dp/B00NF1Q2FS

Thank you once again Barrett for all the links and advice. I will be ordering up the Dorman part.

I appreciate everyone's input here. I'll reach out if I run into any problems along the way.

If you go the Dorman route plug in the new EVA and cycle the ignition switch to make sure it's in the home position before you weld the cam on.

Thank you Starman. I will do that.

Part should arrive later today so hoping to get it all squared up in a few days.

So I've got a quick question... How important is the position of the bell crank on the new Dorman unit? I plugged it in and let it cycle like Starman suggested. It did move to a "home" position.

According to the link that Barret supplied in the thread, the hole (where the cable end attaches) would be in a 2 o'clock position but I've seen pictures of this in an 11 o'clock position (My broken unit was in the 11 o'clock position which I don't want to use as reference).

I have done everything else and I just need to weld the bell crank in place and I do not want to screw up this last, which seems pretty significant, part.

Andrew: Orientation would be with you seated on the bike and looking at the actuator assembly....actuator correctly mounted to airbox lid...airbox cover removed.

The actuator bell-crank rotates COUNTER CLOCKWISE
The actuator bell-crank hole for cable end is at the TWO O'clock position when fully closed
"""""""""""""""""""""""""""""""""""""""""""""""""""""""" ELEVEN O'clock position when pulling cable fully open.

Thank you so much sir. That makes entire sense. Appreciate it.

And an FYI I keep meaning to add is, do NOT twist the actuator by hand. Even with the metal gear upgrade.

and this

34:19 - That’s too funny!

Cooter, They actually printed on the module - Do not rotate by hand.
But that’s great advice as I guess it’s not obvious to everyone so they had to add a warning label.

andrewnel said:

34:19 - That’s too funny!

Cooter, They actually printed on the module - Do not rotate by hand.
But that’s great advice as I guess it’s not obvious to everyone so they had to add a warning label.

Click to expand...

We struggle around here to prevent people from hooking up their battery backwards. I wish I was kidding.

I meant no offense OP:up: Some boxes aren't labelled, and even have a cover for the translucent bikes.







and gasoline is flammable:stupid:



:eagerness: