Altitude surging on 07 fix

[TruWrecks]

This is the first letter that I'm filing, so I'm giving Yamaha the chance to "save face", and do the right thing by it's customers. Orifice enlargement will be the next step. I do think I'm going to refine it a bit more to push for a fix date.

 

[sittonb]

Just remember everybody...I'm selfish, so I'm doing this to get "MY" bike fixed. Everyone else is welcome to tag along though. :lol:

PM Sent, thanks for you work, please include me!!

 

[IanS]

Just had a call from my dealer, new ECU should be in their hands in next 2-3 days.

 

[ELP_JC]

Truwrecks, sent you a PM yesterday with full personal info to be included as well. No staying on the sidelines anymore. Am calling Yamaha right now but no answer; guess they open at 9 PST, so will try again in 30 minutes.

Hey Ian, glad to hear that, but I wonder if they're going to install a baro sensor or not. If not, am afraid the issue won't be completely resolved, but at this point I settle for mild surging. We'll know soon enough I guess. Later gang.

JC

 

[TruWrecks]

They can do without the baro sensor as long as the ECU is checking the intake pressure every few seconds.

Cypress will be open in 12 more minutes.

 

[SANFRANFJR]

Just remember everybody...I'm selfish, so I'm doing this to get "MY" bike fixed. Everyone else is welcome to tag along though. :lol:

Sent you my info also over the weekend. BIG thanks.

 

[TruWrecks]

I just got off the phone with Luke, in Cypress. He's one of the Product Specialists that has spoken with the dealership that I have been working with. He said that Yamaha will should have a corrected ECU ready by the 1st week of October. The dealers should have the parts a few days later. I will be calling my dealer tomorrow to discuss this further because they're not open today. Yamaha figured out who I was when I mentioned the name of the service manager. Luke was very professional, and thanked us for a patience and assistance in tracking down the issue.

I will be stopping by FEDEX later today to send the letter.

I would highly suggest that anyone who has a surger get to your dealer to get your FJR on file. The reprogrammed ECU's will most likely be sent out to the problem bikes on file first.

As far as the 06's that are having some surging, you may want to find a goos service department to work with. The symptoms may be the same, but the cause is likely to be different. My guess is that it may be a TPS or TBS issue that just behaves similar to the 07 issue.

 

[Medium Al]

I just got off the phone with Luke, in Cypress. He's one of the Product Specialists that has spoken with the dealership that I have been working with. He said that Yamaha will should have a corrected ECU ready by the 1st week of October. The dealers should have the parts a few days later. I will be calling my dealer tomorrow to discuss this further because they're not open today. Yamaha figured out who I was when I mentioned the name of the service manager. Luke was very professional, and thanked us for a patience and assistance in tracking down the issue.
I will be stopping by FEDEX later today to send the letter.

I would highly suggest that anyone who has a surger get to your dealer to get your FJR on file. The reprogrammed ECU's will most likely be sent out to the problem bikes on file first.

As far as the 06's that are having some surging, you may want to find a goos service department to work with. The symptoms may be the same, but the cause is likely to be different. My guess is that it may be a TPS or TBS issue that just behaves similar to the 07 issue.

Are you sure the 06 has the baro sensor? I am pretty sure it does not. I am looking at the factory manual now for Gen II (page 7-7, item 12) and it is only showing one for 06 & 07, an intake pressure sensor. I also remember going over the parts fiche diagrams from Gen I and Gen II that Mick provided. The 06 (and the 07) does not have the baro sensor nor does it have the pressure regulator that the Gen I had. To recap Gen I had an intake pressure sensor, a baro pressure senosr, and a pressure regulator. 07 (and 06 as far as I know) had only an intake sensor. If you have heard otherwise from an engineering person then this is significant. Any chance you can verify this? Some strange things going on here.

Furthermore you have said that this person told you the problem was that the one remaining sensor only measured pressure once at start up. This is impossible, the engine needs pressure measurements constantly to decide what fuel mixture to use. And also the surging would not go away under aggressive driving either if that were the case, assuming it was possible in the first palce. Anyway I don't think you are talking to a technical person or a person who understands technical matters.

Al

 

[SkooterG]

Are you sure the 06 has the baro sensor? I am pretty sure it does not. I am looking at the factory manual now for Gen II (page 7-7, item 12) and it is only showing one for 06 & 07, an intake pressure sensor. I also remember going over the parts fiche diagrams from Gen I and Gen II that Mick provided. The 06 (and the 07) does not have the baro sensor nor does it have the pressure regulator that the Gen I had. To recap Gen I had an intake pressure sensor, a baro pressure senosr, and a pressure regulator. 07 (and 06 as far as I know) had only an intake sensor. If you have heard otherwise from an engineering person then this is significant. Any chance you can verify this? Some strange things going on here.
Al

I don't see where he mentioned anything about the baro sensor.

I think it's pretty much a given that the Gen II FJRs (06 & 07) DON'T have the the 2nd sensor - the baro sensor, that the Gen I bikes have. So it's NOT a baro sensor problem as most 06 bikes work fine. IOW, there were no hardware or sensor changes from 06 to 07. So the problem must be some sort of software isse (ECU). So

So to me, an ECU change, or fix, seems logical, as it seems somehow the ECU stopped sampling the intake pressure for FI adjustments from 06 to 07.

 

[Medium Al]

Are you sure the 06 has the baro sensor? I am pretty sure it does not. I am looking at the factory manual now for Gen II (page 7-7, item 12) and it is only showing one for 06 & 07, an intake pressure sensor. I also remember going over the parts fiche diagrams from Gen I and Gen II that Mick provided. The 06 (and the 07) does not have the baro sensor nor does it have the pressure regulator that the Gen I had. To recap Gen I had an intake pressure sensor, a baro pressure senosr, and a pressure regulator. 07 (and 06 as far as I know) had only an intake sensor. If you have heard otherwise from an engineering person then this is significant. Any chance you can verify this? Some strange things going on here.
Al

I don't see where he mentioned anything about the baro sensor.

I think it's pretty much a given that the Gen II FJRs (06 & 07) DON'T have the the 2nd sensor - the baro sensor, that the Gen I bikes have. So it's NOT a baro sensor problem as most 06 bikes work fine. IOW, there were no hardware or sensor changes from 06 to 07. So the problem must be some sort of software isse (ECU). So

So to me, an ECU change, or fix, seems logical, as it seems somehow the ECU stopped sampling the intake pressure for FI adjustments from 06 to 07.

I agree with you, that is what I am pointing out.

Read first post here, asserting 06's have the sensor and 07's don't:

https://www.fjrforum.com/forum//index.php?showtopic=23179

Furthermore the sensor can't possbily only read pressure at start up, the bike would not run.

 

[LarsBo]

Regarding the statement "Furthermore the sensor can't possbily only read pressure at start up, the bike would not run".....

In programming the ECU it should be a simple matter to read an input once and hold that value until you re-read or re-sense the input again. For which the 07 FJR apparently doesn't do until either shut off or a throttle response of greater than 20% happens. So we're told anyway.

I'm no motorcycle Engineer but I know Control Systems. Configuring air/fuel controls on a boiler or heater in a refinery is similar. Only there's no jockey whacking a throttle every second or two. Still, the system needs to be responsive to changes in input - if not done right the results can be catastrophic.

One of my good friends, also a Control Systems Engineer, while designing controls for a Nuke plant used to often say sarcastically, "Sure it's good enough for a Nuke, after all it's not for anything as important as a motorcycle". He rode a classic BMW boxer and was always good for words of wit and wisdom.

The FJR ECU is providing very fast "resolutions" for adjusting air/fuel mixture valves (or whatever they call the valves on a motorcycle). Even in the earlier "no problem" FJR's the ECU is probably not reading a live analog pressure input for each and every valve resolution. It probably reads the held value; but obviously get re-sensed more frequently than on the problem 07 ECU's.

If indeed this is the real (and only) problem, it would be simple enough to rewrite the code to re-sense the one atmospheric pressure input more frequently to accommodate any changes in altitude. You could probably do this once every 30 or 60 seconds (or longer) and still be problem free. The software guy was probably supposed to do that in the first place when they took the "extra" sensor out - but for whatever reason it got missed.

Just speculating of course. But in the good old days when Engineers ruled (so to speak) less of these kind of things happened. We now however, live in a world ruled by bean-counters and lawyers, no offense intended.

 

[Medium Al]

Regarding the statement "Furthermore the sensor can't possbily only read pressure at start up, the bike would not run".....
In programming the ECU it should be a simple matter to read an input once and hold that value until you re-read or re-sense the input again. For which the 07 FJR apparently doesn't do until either shut off or a throttle response of greater than 20% happens. So we're told anyway.

I'm no motorcycle Engineer but I know Control Systems. Configuring air/fuel controls on a boiler or heater in a refinery is similar. Only there's no jockey whacking a throttle every second or two. Still, the system needs to be responsive to changes in input - if not done right the results can be catastrophic.

One of my good friends, also a Control Systems Engineer, while designing controls for a Nuke plant used to often say sarcastically, "Sure it's good enough for a Nuke, after all it's not for anything as important as a motorcycle". He rode a classic BMW boxer and was always good for words of wit and wisdom.

The FJR ECU is providing very fast "resolutions" for adjusting air/fuel mixture valves (or whatever they call the valves on a motorcycle). Even in the earlier "no problem" FJR's the ECU is probably not reading a live analog pressure input for each and every valve resolution. It probably reads the held value; but obviously get re-sensed more frequently than on the problem 07 ECU's.

If indeed this is the real (and only) problem, it would be simple enough to rewrite the code to re-sense the one atmospheric pressure input more frequently to accommodate any changes in altitude. You could probably do this once every 30 or 60 seconds (or longer) and still be problem free. The software guy was probably supposed to do that in the first place when they took the "extra" sensor out - but for whatever reason it got missed.

Just speculating of course. But in the good old days when Engineers ruled (so to speak) less of these kind of things happened. We now however, live in a world ruled by bean-counters and lawyers, no offense intended.

If it were only a matter of not reading throttle position soon enough, the problem would be permanently cleared by opening the throttle more than that amount. That does not happen so it is not a suitable explanation for the behavior we are seeing. The ECU gets progressively confused and after a certain point and no amount of throttle will help unconfuse it. Furthermore the WOT every so often only gets you another few hundred feet of elevation gain at most, prior to going into seizure mode. Whereas stopping and starting again gives you another 1500 ft.

It is not just a surging problem, the surging is the final manifestation of a continuous mixture problem, due to the system not being able to measure pressure accurately anywhere but (maybe) constant altitude. This has led me to speculate that it is a filter or time series estimate of the pressure that is screwed up, so maybe just changing the filter coefficients (or upping the sample rate) will fix it.

 

[quietguy]

I don't wanna throw water on all the technical discussion (I'm lucky to put the right shoe on the correct foot), my primary and only concern at this point is that Yamaha FIX the freakin' problem.

Now, back to the techie folks :dribble:

 

[Medium Al]

I don't wanna throw water on all the technical discussion (I'm lucky to put the right shoe on the correct foot), my primary and only concern at this point is that Yamaha FIX the freakin' problem.
Now, back to the techie folks :dribble:

Hey I'm all for that too. Problem is I think Yamaha let us do all the debugging on this and if they are fixated only on surging they will miss the boat. This thread started with someone claiming they had insider info from Yamaha saying they'd tracked it down to the only measure pressure after 20% throttle thing. And I am trying to point out that is complete BS. Someone else at Yamaha has been telling TruWrecks that 06's had baro sensors and 07's did not, and that was the problem. Complete BS as well, etc. etc.

 

[quietguy]

I don't wanna throw water on all the technical discussion (I'm lucky to put the right shoe on the correct foot), my primary and only concern at this point is that Yamaha FIX the freakin' problem.
Now, back to the techie folks :dribble:

Hey I'm all for that too. Problem is I think Yamaha let us do all the debugging on this and if they are fixated only on surging they will miss the boat. This thread started with someone claiming they had insider info from Yamaha saying they'd tracked it down to the only measure pressure after 20% throttle thing. And I am trying to point out that is complete BS. Someone else at Yamaha has been telling TruWrecks that 06's had baro sensors and 07's did not, and that was the problem. Complete BS as well, etc. etc.

If Yama only goes part way and the problem remains, gonna be a pretty big loss of business, and a whole bunch of used FJRs on the used bike lots.

 

[TruWrecks]

Folks,

From Yamaha (and confirmed today): "Yamaha has admitted that they removed the sensor in the 2007 that samples the air pressure during operation (The 2006 has this sensor). The 2997 ECU can be forced to re-sample intake pressure by turning the throttle 20 deg or more, or by shutting down the ignition and restart it."

If you want to argue about it, take it up with Yamaha Corp in Japan. I know someone from Okinawa if you need a translator! For now, we have about 1 week left before we'll see anything.

Cheers.

 

[Medium Al]

Folks,
From Yamaha (and confirmed today): "Yamaha has admitted that they removed the sensor in the 2007 that samples the air pressure during operation (The 2006 has this sensor). The 2997 ECU can be forced to re-sample intake pressure by turning the throttle 20 deg or more, or by shutting down the ignition and restart it."

If you want to argue about it, take it up with Yamaha Corp in Japan. I know someone from Okinawa if you need a translator! For now, we have about 1 week left before we'll see anything.

Cheers.

Well thanks for the confirmation at least, even though it confirms whoever you talked to may not understand their own products. Let's see what they come up with.

 

[jestal]

I think you guys may be misunderstanding how the MAP sensor could provide an estimation of the BARO value.

MAP is the Manifold Absolute Pressure. MAP will change as the engine is throttled. MAP is low at idle and part throttle and high, nearly equal to the barometer at higher throttle openings.

If the ECM looks at the MAP at higher throttle openings then it can form a good approximation of the Barometric pressure.

As long as the engine is throttled (run at part throttle) there is no way the ECM can approximate the Barometer based on the MAP reading.

As has been described before, when the barometric pressure sensor is eliminated there is some software added to the ECM logic path to look at the MAP sensor under certain conditions to estimate the BARO term.

When the key is turn on, just before cranking begins, the MAP sensor is reading pure BARO (since barometric pressure is entering the throttle body and there is no restriction) so the FJR ECM likely takes a BARO reading at key on and remembers it as has been discussed.

Once the engine is running the BARO can be updated any time the throttle is opened enough to achieve and unthrottled condition. Unthrottled does not mean WOT....nor does it mean 20%. At low RPM the throttle only has to be opened a small amount to achieve an unthrottled condition, easily identified by a vacuum level of zero. As the RPM increases the throttle needs to be opened further and further to achieve zero vacuum or unthrottled condition where MAP would be equal to BARO.

It seems like bad information, or a gross oversimplification, to say that the BARO would be updated by opening the throttle past 20% under all conditions as implied. If you were lugging the engine at 2000 RPM in high gear then 20% throttle probably achieves unthrottled condition or zero manifild vacuum and would provide an excellent baro-less approximation. At 7000 RPM 20% throttle would still achieve a fair amount of manifold vacuum and the MAP reading would be useless to approximate BARO...and could cause a huge error in the baroless approximation if Yamaha is trying to do that. THat is why "baro-less" sensor algorithms start with a look up table of RPM and throttle opening to establish the throttle opening at any given RPM that the BARO could be updated.

In addition to the varying throttle opening requirement (vs. RPM) the fact that there is some restriction in the inlet path that must be accounted for. At low RPM (low flow) the restriction of the air box/aircleaner/induction tubes/throttle body is virtually zero so MAP observed when unthrottled at low RPM will very nearly equal BARO. At 7000 RPM there is probably several kPa pressure drop (just guessing) across the induciton system so the MAP at unthrottled 7000 RPM might equal BARO if 2 or 3 kPa were added to it. Most "baro-less" routines that I have run across in automotive control systems have a separate lookup table of MAP offset vs. RPM.

When the correct throttle opening is achieved from the first lookup table the baro-less routine samples MAP and then adds the appropriate offset to the MAP term to approximate BARO. If this is calibrated correctly the "baro-less" routine can very very accurately approximate the true baro reading and update it frequently whenever the throttle is opened sufficiently to achieve (nearly) unthrottled conditions.

The fact that some riders seem to experience no change when opening the throttle past 20% and others do is easy to explain by the effect of RPM. Open the throttle past 20% at low RPM while lugging the engine and a good baro update could occur. Open the throttle 20% at 5000 RPM would result in an inaccurate baroless update and could make the situation worse or better or not change it. Hard to predict but the results mentioned easily fit my preconcieved notions of how a baro-less routine works.

The fact that Yamaha has seemed to acknowlege a problem with the barometer (via a clearification...???) seems to confirm that suspicions about the lack of a baro sensor early on were correct.

The fact that they appear to be replacing the ECM for a fix (per what is posted above....true??) seems odd. One would think they could reflash the existing ECM if it was a simple calibration error or shortcoming. Possibly some new hardware is being added internal to the ECM?? It is not unheard of to have the baro sensor mounted directly on the circuit board of a controller. Possibly that is the fix??

Maybe, just maybe, the 06 ECM's had the Baro sensor on the ECM circuit board and this was eliminated in 07. No one would have known about the baro sensor on the board in an 06 if it had one. If this was the case then the 07's might have a problem with an inadequate baro-less approximation that wasn't required in 06. Maybe the ECM is going to be retrofitted with (what amounts to..) an 06 ECM. This would jive based on the statements from Yamaha that the 06 had the baro sensor and that it was eliminated for 07. This is pure speculation. Pure speculation. I'll have to look at the Yamaha parts website to see if the ECM changed PN from 06 to 07. Edit: The ECM part number is different between 06 and 07 so something changed inside of it even though the fuel injection hardware seems to be the same between the two.

Or, possibly there is a hard coded chip on the ECM circuit board that does the analog to digital conversion from the MAP sensor that is being changed to effect a more accurate baro-less approximation. Or, maybe yamaha ECM's do not have full software flash capability. Possibly part of the operational code in the ECM is masked into the CPU. Changing that would require a re-masked CPU chip thus requiring a new ECM to revise the baro-less logic.

All this is speculation. It is possible to have a fuel injection system (like on the FJR) to work perfectly fine without a baro sensor. There are millions and millions of baro-less cars running around doing fine. If the system has no baro sensor and there is a clear problem with the baroless approximation (pretty fair to conclude at this point about the 07 FJR) then someone simply did not do their developmental homework and/or made a last minute change to the baroless approximation without revisiting altitude.

I still think that the surging on the 07's is a combination of a base fueling table inaccuracy COMBINED with the baroless error at higher altitudes.

 

[jestal]

The FJR ECU is providing very fast "resolutions" for adjusting air/fuel mixture valves (or whatever they call the valves on a motorcycle). Even in the earlier "no problem" FJR's the ECU is probably not reading a live analog pressure input for each and every valve resolution.

The "air/fuel mixture valves" are called fuel injectors. The ECM calculates an amount of fuel required for each cylinder event (each intake valve opening or every other crank revolution) and electrically opens the fuel injector for a calculated time or pulse width to deliver the correct amount of fuel. The injector pulse width is usually expressed in milliseconds of time that the injector is turned on each time. I would guess that the MAP sensor data is read several times betweening intervening injector pulse width calculations. The ECM is that fast, yes. It is probably not updating the baro-less term that fast, though.

If there is an error with the lack of a baro sensor it likely occurs when the ECM calcutes the amount of fuel needed, not in the actual injector opening.

There is another possible problem, though, associated with the injector. As mentioned earlier, the 06/07 engines have a returnless fuel rail. Therefore the pressure drop across the injector (from the fuel rail to the intake manifold) is not always the same. If the injector pulse width correction for the varying pressure drop is using the baro-less term to approximate intake vacuum then a poorly done baro-less value certianly could cause fuel injection errors at the injector.

 

[Medium Al]

jestal,

This is great info and speculation, thanks.

Al