Noob Question: Should the Engine Stop Switch Ever Be Switched Off?

[masa]

Originally Posted by Cburt

Do whatever you want. No amount of evidence or logic can convince some people.

I can't care less about how other people turn off their engine

I'm a software engineer and was a bit curious about "the damage" to the ECU whose memory, as I understand it, does not evaporate when the bike is turned off, whether by the ignition key or the kill switch. In a way, I'm waiting to be convinced

[bira]

The manual clearly states:
"Although the engine stop switch stops the engine, it does not turn off all the electrical circuits and may cause difficulty in restarting the engine due to a discharged battery. Ordinarily, only the ignition switch should be used to stop the engine."

No mention of potential damage, but why leave circuits live when the point is to shut everything down? You do want to keep your battery in good shape, right?

[Marco]

What I suppose, could be affected is the adaptive values, but adaptive values shouldn't be able to damage the bike, as they're minor adjustments? Also the ECU shouldn't allow for extreme adjustments, but others here are probably be better able to answer those two assumptions.

As with operating systems, your mileage may vary, mine survive powercuts just fine

[masa]

Originally Posted by bira

You do want to keep your battery in good shape, right?

Sure. I tend not to forget to pull out the key though. I try to park on an uphill slope when possible and it's handy that I don't have to take my right hand off the bar. If I forgot to pull out the key a couple of times, I'd consider changing the "sequence" to "ignition off -> Run switch off". So far, "Run switch off -> ignition off" makes more sense to me.

Originally Posted by Marco

What I suppose, could be affected is the adaptive values,

Yeah, if the ECU has RAM that keeps data while the engine is off, i.e. is a self adjusting type, technically there is a chance the values get messed up. That's really "technically" though. It's less likely a power cut to the fuel pump and/or the plugs would later cause something like leaner mixture or earlier detonation. Of course, I haven't actually seen the program, so I can't say for sure, but I think the possibility is pretty close to zero, or if it does happen, that's more like a bug which can happen even with turning the ignition off. Anyways, I never had any issue either

[DEcosse]

Originally Posted by triplestrength

I give up urban myth obviously accepted....

Just to add my support, TS - I share your frustration

Total nonsense that there is any difference between Kill and Key-Switch as far as the bike's engine/ running/control system - the ONLY difference is that key-switch has additional poles (unrelated to engine control) for lights and ancillaries. The Key-Switch and Kill are directly in series with one another and perform IDENTICAL functions to break the circuit at exactly the same node re ignition/ECM/Fuel Pump/Injectors/Coils and anything else engine related.
I'll challenge anyone who says differently to show TS & me the circuit path through the key-switch that shows otherwise. TS & I can both read schematics - we're not making this stuff up.
I don't care about other marques or generalities, this is specific to Triumphs.

Originally Posted by JCP

.... but the complexity of an ECU controlled electronic fuel injection system which reads a number of electronic sensors and resets itself checking each sensor and comparing actual readings with expected readings and cycling the icv is not meant to be stopped in it's tracks by simply cutting power.....

That is false - the circuit is cut at exact same node whether key-switch or Kill switch

Originally Posted by k12techman

... Yeah, you can do it and it might not cause you problems the first few times, but eventually, it's gonna cause damage.....

It will not - exactly same either way

Originally Posted by Orangeman

... makes it harder to start since the last thing the ECU/sensors see is the fuel pump relay being interrupted and the engine stopping from a lean condition rather than the ECU recognizing an intended shut down. ....

Totally incorrect - the shut-down sequence is the same - please show on the schematic how the circuits differ for each switch being interrupted and what is being cut/not cut in one vs the other. (lights and ancillaries not included)

Originally Posted by Marco

What I suppose, could be affected is the adaptive values, but adaptive values shouldn't be able to damage the bike, as they're minor adjustments? ...

There is no way for the adaptive values to be affected or lost, even when you totally disconnect the battery.

Originally Posted by masa

Yeah, if the ECU has RAM that keeps data while the engine is off, i.e. is a self adjusting type, technically there is a chance the values get messed up.

There is not any possibility of this happening

All of the above is speculation people - instead of 'thinking' what/how it might be different, look at the schematic and see where there are real differences

The Triumph Owners Manual caution against using the Kill/Run to shut off engine simply & specifically because that will leave lights and ancillaries powered if the key-switch is not subsequently turned off.
That is good advice - just use the key-switch to avoid potential of forgetting and draining battery.

[bira]

Originally Posted by masa

Sure. I tend not to forget to pull out the key though. I try to park on an uphill slope when possible and it's handy that I don't have to take my right hand off the bar. If I forgot to pull out the key a couple of times, I'd consider changing the "sequence" to "ignition off -> Run switch off". So far, "Run switch off -> ignition off" makes more sense to me.

As long as the ignition key is turned off, it is off, regardless of sequence.

[masa]

Originally Posted by DEcosse

There is no way for the adaptive values to be affected or lost, even when you totally disconnect the battery.

There is not any possibility of this happening

I agree, the caution in the owner's manual is more than likely just to keep people from forgetting to turn the bike off. Generally speaking though, adaptive values of an ECU are stored in battery and capacitor backed up memory and it WILL evaporate/be lost if you disconnect the battery long enough, say one hour. And the ECU could most likely detect the state of the kill switch from the difference in the voltage pattern. So, someone could write a program, intentionally or unintentionally, that does wacky things only when the kill switch is activated. But then again, bugs can happen anywhere, with kill switch on or off, so not using kill switch doesn't make sense unless we are sure there is an issue with the ECU software.

Originally Posted by bira

As long as the ignition key is turned off, it is off, regardless of sequence.

Yes. Long time ago, I once left the key on the bike for a day at work and then thought maybe I should make it a habit to turn off the bike with the key and immediately pull it out. But that was with my old bike. I don't feel I would ever do that to my Streety, 'cause I have to stare at and admire it for like a minute every time I get off the bike

[DEcosse]

Originally Posted by masa

... Generally speaking though, adaptive values of an ECU are stored in battery and capacitor backed up memory and it WILL evaporate/be lost if you disconnect the battery long enough, say one hour.

For short term trims maybe, don't know one way or the other to be honest - but who cares about those anyway;
my understanding is that the long term trim is maintained in NVM - you can read the value in TuneECU and over-write/zero it as you see fit.
But I will also add that there is no constant power to the ECM - therefor what you are suggesting is that if bike is parked for an hour, that adaptive trim is lost? Don't think so!

.... And the ECU could most likely detect the state of the kill switch from the difference in the voltage pattern. So, someone could write a program, intentionally or unintentionally, that does wacky things only when the kill switch is activated. ...

The Key-switch and Kill/Run switch are directly in series with each other, with no parallel branch nodes off the connection between them; so when power is broken at either one, there is no way of the ECM possibly knowing which it was that removed the power from the circuit and how that turn-off transient, which would likely be quite different each time, especially depending on the instantaneous current load at that moment, could be used to derive any meaningful deduction from a voltage perspective. And of course the ignition voltage is not exactly tightly regulated anyway subject to fairly big deviation from engine rpm & load changes. So regardless how sophisticated the sense/ detector circuit, don't see any possibility it could possibly tell which switch was turned off
But the simple questions is, why would that requirement be even necessary to go to such lengths to try to detect which is operating, given the exact same functionality of either?

[Orangeman]

Originally Posted by DEcosse

The Key-switch and Kill/Run switch are directly in series with each other

I am more than willing to learn, could you please show me .......

1 is the instrument cluster
4 is the stop switch
6 is the ECM
27 is the fuel pump relay
40 is the alarm connector
48 is the ignition switch

I can e-mail you a PDF file with a clear scan of the Street Triple circuit diagram and full key, it is too large to post here.



.

[Cburt]

Originally Posted by Orangeman

I am more than willing to learn, could you please show me .......

1 is the instrument cluster
4 is the stop switch
6 is the ECM
27 is the fuel pump relay
40 is the alarm connector
48 is the ignition switch

I can e-mail you a PDF file with a clear scan of the Street Triple circuit diagram and full key, it is too large to post here.



.

Please don't confuse the issue with the facts.