CB1100 Idle speed instability problem

[johnf514_imp]

Hi Beardy, great write-up. Hope your trip to the states goes well.

I requested that the dealer not reset the ECU until they had resolved the high idle condition through other means. I think the ECU reset is a temporary fix, and the condition returns after a couple of months (this occurred multiple times).

I hope the high idle condition does not return for you, but if it does, I recommend requesting the dealer not mask the condition with an ECU reset.

 

[beardyweirdy@me.com_imp]

Hi Beardy, great write-up. Hope your trip to the states goes well.

I requested that the dealer not reset the ECU until they had resolved the high idle condition through other means. I think the ECU reset is a temporary fix, and the condition returns after a couple of months (this occurred multiple times).

I hope the high idle condition does not return for you, but if it does, I recommend requesting the dealer not mask the condition with an ECU reset.

Thanks John,

Did your dealer install a newer/latest version of the software on your ECU, when they reset it? Don't suppose they gave you a slip of paper with the version No. or ID did they?

I tend to agree that they may just be writing a setting to the ECU to ignore a warning or voltage change from a faulty component. It's much cheaper and faster to re-write the ECU than to remove the Throttle Bodies and replace, say, the IACV. I'll try this fix out and report back. If the problem comes back then I'll investigate components.

I am a bit disappointed that Honda haven't released a bulletin, stating the fix and what they have changed. I don't like not knowing what the problem is! I know it shouldn't matter but I'd just like to know!! ;-))

 

[the Ferret]

Something I don't understand, If the ICAV unit is the issue with the idle on some CB1100s, and that ICAV unit is used on many different Honda models, as previously stated, why have we not read about idle issues with those other models. There must be a million bikes around the globe running this unit. Confusing for me.

 

[DaSwami_imp]

Something I don't understand, If the ICAV unit is the issue with the idle on some CB1100s, and that ICAV unit is used on many different Honda models, as previously stated, why have we not read about idle issues with those other models. There must be a million bikes around the globe running this unit. Confusing for me.

Which is another way of saying maybe it is the ECU??

 

[beardyweirdy@me.com_imp]

It maybe!!
Could be the way the ECU interprets info is leading to the problem.

Could it be a faulty batch of ICAV's? Again maybe...

There seems to be a fair number of people in the Far East who've had the problem fixed with the re-flash.

Either way, component or ECU if it works, it works.... but I still would like to know why! ;-)

I might call Honda UK back and ask for some further info, they were really good when working out with the dealer why they couldn't upload the new software first time around.

 

[the Ferret]

I'd like you know why as well, mainly because I'm curious about thingsand think everything can eventually be figured out logically..... and this one is driving me nuts.

 

[johnf514_imp]

Beardy, the ECU was reset the first two times I took the bike into the dealership. As far as I know, there was no reflash of the software in the ECU.

Ferret, I agree with you that the IACV is used across millions of vehicles. It could be that a small batch of parts were faulty, and for some reason were unleashed on our bikes. For reference, my bike is a 01/2014 model.

It could very well also be the ECU, but I can state that in my experience, the first two resets of the ECU did not permanently cure the issue.

 

[Magnus_imp]

I wonder if this IACV is used on any other air cooled motors? Maybe there is a difference in the temperatures the IACV is exposed to.

 

[dave]

Hey All,

Just thought I'd let you know how I was going on with the on going Idle Prob.

I managed to get the bike back to the dealers yesterday and they successfully re-flashed the ECU with the latest Map from Honda. I'm not sure why it worked this time but I had called Honda UK to question what was going on and they offered the dealer some tech support and pos. a new disk/Software.

The dealer gave me a 'Honda ECM Update Report'. It states the previous ECUID which is 01019D0102
and an After the Update ECUID of 01019D0103. I don't know if this is specific to my bike or a general code for the re-flash.
There is also a note at the end of the report giving the code: 38770-MGC-D53_-M1.rwf.
I have no idea what that code refers to but it's the only other info on the report that isn't obvious stuff like date, VIN, milage etc....

After the re-flash I gave it a celebratory thrashing followed by a 30 min trawl thru London rush hour traffic, trying my best to emulate the riding style that had usually preceded the fault. It has mainly occurred when two up in town and dawdling. I was on my own yesterday but I road as tho I was carrying a pillion. I dragged the back brake to put the motor under load and slipped the clutch. I also sat in traffic and didn't cut thru and lane split so much as I would do with someone on the back.

I couldn't get it to show the fault. I let the revs fall to tick over and they stayed solid at 1050. Now I don't know if it will stay like that. We'll have to see what happens over the next week or so. I have a week or so at home so I'll be taking my girlfriend into work most days next week. That will give us a good test. But I'll keep my eye on it and report back.

On a side note, It has reset all the good things that Guhl Motors did to my ECU. I'm going to the USA on a work trip in a couple of weeks, so I'll take my ECU with me and get it re-done while I'm there.

I have spoken to Don at Guhl perviously and he's expecting the ECU. He said he'd go through it, work out what Honda had modified and then re-write their map to incorporate the Honda modifications.

I guess that way there is an option for you guys in the states to get the new map, via Guhl, if Honda USA isn't offering it to their customers.... if it works that is ;-)

It is interesting that the IACV replacement/overhaul seems to be working for some. I was going to test mine, as per the manual and see how it faired. Dave, did you run thru the diagnostic test in the manual? if so what did you find?

I'm not going to change anything else for a while tho, so I can really see if the new map is working for me .... Only change one thing at a time when testing and all that.

Which is another way of saying maybe it is the ECU?? The fact that unplugging my EOT sensor completely cures the idle problem (both high RPM and Low RPM / stalling) makes me believe it's the ECM, and not the IACV.

 

[Lord Popgun]

Dave, the IACV checkout is in the fuel system section 5, page 5-41 in the '13/14 manual.

 

[beardyweirdy@me.com_imp]

Thanks Popgun, beat me too it...

Dave, it's a series of tests, with a meter I think, to check over the IAVC. You do them all from the connector, so you don't have to tear it down to the throttle bodies.
Worth a look, was thinking of doing mine next week as I'm stripping her back a bit for a pre-spring overhaul.
Just curious really, I haven't had the Idle prob. since the re-map...

 

[dave]

Dave, the IACV checkout is in the fuel system section 5, page 5-41 in the '13/14 manual.

Thank you Popgun.
Visited the Honda dealership yesterday where I purchased my bike armed with about 20 pages of screen prints from this forum link, and of course the full information of Beardy's re-mapping information. They politely told me to go pound sand. They informed me they had no information from Honda about a recall or any service bulletins on this bike, and any re-mapping information released by Honda for England would absolutely not be applicable to a bike sold in "Emissions Stringent" California. The Service Advisor politely advised me to "contact Honda directly and take it up with them" (which I will do). I convinced the Service Advisor to read the posts on this forum, and he agreed to contact Honda and relay the information to them and discuss the situation to see what he could learn. I am sending an email to the Service Advisor with a link to this forum and he promised to read the links. FYI - rode the bike on a 130 trip today on mostly back country roads and it ran perfectly. Of course the problem only surfaces when the motor idles, but I did stop at about a dozen stop signs.

 

[beardyweirdy@me.com_imp]

That's annoying Dave,
They could be right in that the re-map adjusts the perameteres or the ECU as to make it fall foul of environmental regulations.

I'm coming over to the USA next week and I'm bringing my ECU over for Don at Guhl to adjust. He's going to take off the restrictions and limiters. While he's at it, he said he'd look to see what Honda had changed from the Std. Map.

Providing he can see what mods have been made, he'll have a map available to load into ECU's in the US that have the problem... it's an option, hopefully.

 

[dave]

That's annoying Dave,
They could be right in that the re-map adjusts the perameteres or the ECU as to make it fall foul of environmental regulations.

I'm coming over to the USA next week and I'm bringing my ECU over for Don at Guhl to adjust. He's going to take off the restrictions and limiters. While he's at it, he said he'd look to see what Honda had changed from the Std. Map.

Providing he can see what mods have been made, he'll have a map available to load into ECU's in the US that have the problem... it's an option, hopefully.

Hi Beardy, thanks. Where in the states? If you're in San Diego I'll buy you dinner!

 

[beardyweirdy@me.com_imp]

Hey Dave, that's a kind offer! I'm in LA for a bit then Mohave, moving north to Saltlake City, Denver and Seattle.

To be honest I wish I was going down to SanDiego, love that city.... another time, for sure.

If it's any use, I called Honda to ask what had been changed on the ECU. They got back to me with an email, which said.

"... the ECM was rewritten as the parameter for the idle control valve was slightly incorrect .
It was a very straight forward update and should be trouble free now. "

Honda UK have been really good to deal with. Always get back to me, promptly, and are very helpful.

What they say makes sense. Let's hope it's all sorted.

I've been in the thick of it, in town, today. Loaded up, with a pillion, rain, traffic, lots of stop start, I stalled it at lights and later ran out of fuel!! Quite a day, but idle has been spot on. Not a fault so far.

In fact the bikes been fantastic and I still love it! Only downside was the shocking mpg I got. When I drained the tank it gave me a good opportunity to work out my Mileage. 30 mpg to a UK gal. And 25 to a US gal.
Super low.

 

[johnf514_imp]

Beardy, that's great to hear about the idle not returning. Hopefully the low MPG is the result of the bike relearning fueling, or maybe just the nature of the stop start traffic and riding with a passenger.

Ride safe.

 

[the Ferret]

Is an ECM the same thing as an ECU just different language?

Lets hope this puts an end to your idle issues Beardy, however now I'm confused about the 25 U.S. mpg when many of us are in the low 50s. I would think 40-42 might be feasable in all around riding , which included stop and go and freeway and back roads terrorizing, but 25? That does not seem reasonable.

 

[Lord Popgun]

Engine Control Module, Engine Control Unit. Whats one letter among friends? I think some manufactors use one some the other.

Beardy is British they say bonnet, we say hood. Or trunk and boot?

Yeah, I watch Wheeler Dealers.

 

[Jonz_imp]

I get a low MPG of 30-33 on my daily commute, have since 2014. In less stop & go it goes into the 50's. Beardy if you want to have beer together in Seattle let me know. Jonz

 

[the Ferret]

Engine Control Module, Engine Control Unit. Whats one letter among friends? I think some manufactors use one some the other.

Beardy is British they say bonnet, we say hood. Or trunk and boot?

Yeah, I watch Wheeler Dealers.

So, it's physically the same part right.

Jonz... wow that stop and go must really be a gas sucker. I don't stop and go much, usually just go lol. Even brand new I have never, ever gotten below 49 mpg (except maybe on 1 extended stint of freeway riding at 80 mph I think I got something in the 40's on one fill) and have gotten as high as 64 mpg, but average 55-57 mpg.