Triumphrat

oldndumb · 05-09-2007

Is there anybody using the stop switch? I was wondering because I picked up on a rumor that it causes an ECM reset. I never use mine, but am interested in hearing from someone that does.

CLB · 05-09-2007

My dealer told me that usage of the stop switch would confuse the ECU.
They also told me the trip computer is useful for timing quarter mile runs...

Fact is that the kill switch is wired in series with the key. Either will cut power to the engine control relay coil, bringing the ECU down in the same manner.

JasonS · 05-09-2007

if'n you check through the forum using search, you'll find this one has been answered many times... and that answer is

The ECU doesn't get a chance to "close down and record last known good setting for the engine, and can create running issues. Computers tend to not like having the power pulled, they would prefer to shut down gracefully... using the kill switch cuts power to the computer, thereby crashing it.... when it powers up again, it likely checks for proper shutdown from the last run cycle. When it finds that the last cycle didn't end the way it should it *may* do something...

Resetting the ECU ... ???

I know that if you disconnect the battery, you'll get a check engine light for three consecutive run/hot/cool cycles....

To recalibrate the ECU, one should take a nice long ride to get everything up to temp and upon returning home, do not shut it off, but let it idle for 10-15 minutes whiteout touching the throttle or anything else, by this time the cooling fan should be running all the time or most of the time ( unless it is cool outside), doing this will allow the ECU to recalibrate to the best settings for the current condition. I'd guess that anytime you have a drastic change in altitude or climate this would be a recommended procedure to get the best performance form the engine.

(Older Saabs had a similar ECU recal routine where by you started at the bottom of a long hill and at about 35 in 4th gear, then floor it up the hill, pegging the throttle and turbo gauge until you get over 5500 rpms. ( at which point one is going 90 or so)

duckie · 05-09-2007

I use the kill switch everytime I turn off the bike - a throw back to the advice given me on my MSF course. That being in a crash scenario if you by habit turn off your bike using the kill switch, you will be much more likely to use the kill switch when you really need to use it i.e crash with fuel leak and or crash with bike in gear on its side back wheel spinning madly... etc...

But I had no idea that it affected the ECU! JasonS - is that Triumphs official stance on the kill switch affecting the ECU? How does turning off the bike from the key differ than the kill switch in terms of shutting the ECU down? Surely they both cut power to the ECU? :???: :???: :???:

Of course my sv650s doesn't have an ECU so that's my excuse and I'm sticking to it... :hammer:

PaloAlto · 05-09-2007

I'm with CLB. The wiring diagram indicates no difference in powering off via the switch or key. There is no "delay timer" that provides juice to the ECM after the key is off.

The analogy with computers is whether a desktop computer sees a difference beween using the switch on the power supply (kill switch) or pushing the button in front which, on my computer, also immediately cuts the power. The bike has no software button as in Windows that initiates a "soft" shutdown.

And, yes, folk at the dealers do say the ECM may be confused by the kill switch. But I think that's motorcle myth, not reality.

Nonetheless, I always use the key, in part because the headlight is not powered off by the kill switch. So, use the key. But not because the kill switch can confuse the ECM.

Bern

CLB · 05-09-2007

Check a wiring diagram.
On 05+ at least kill switch = ignition key as far as shutdown is concerned.
Either will chop power to the ECU in the same non graceful manner.

The ignition switch is fed by an always live 10A fuse.
The kill switch is fed by the ignition switch.
The line then feeds through the alarm or alarm bypass connector.
Then on to the engine management and fuel pump relay coils.

The other end of the engine management relay coul is grounded so ECU is powered wnenever ignition and kill are conducting.

The ECU decides when to ground the fuel pump relay coil return.

The ECU relay draws power from a 20A fuse and simultaneously powers or interrupts:
Ignition coils
Purge valve connector
Cooling fan relay coil
ECU
Injectors
Air injection solenoid
O2 sensor

The instrument panel is provided with an unswitched power source but the ECU is not.

So:
Either switch simply chops power to the ECU (and other items listed above.
It makes no difference to the ECU but it might to you if you forget to turn the kill switch back on.

duckie · 05-09-2007

PaloAlto I'm guessing this subject ranks up with oil and tire choice in terms of widely differing opinions... But I'm glad you pointed out that the key and kill switch seem to have the same affect on the ECU in terms of shutting down. It didn't make sense to me that the key would shut the ECU down in a different way to the kill switch unless it still had some power going through it. Which brings me to the next point - with the key, it really does cut all the power i.e no lights but with the kill switch the lights stay on... so maybe it's the otherway around? (just a thought).
I use the kill switch to shut down the engine and then I turn it off at the key so in reality I'm doing the same as you but just with an extra step... I still like the MSF theory... so I may just going on using the kill switch until I hear a better arguement for not using it... but this has made me unsure about that - ignorance is bliss! :hammer:

CLB · 05-09-2007

Lighting is another circuit.

The headlight relay coil is powered directly by the ignition switch as there is no need to run this through the kill switch.

The high current source to the headlight relay is however switched by load dump contacts in the starter relay. Headlights are non-essential to the engine so that high load is dropped while the starter is cranking.

JasonS · 05-09-2007

Ok, then...

Someone kidnap at put at gun point a Triumph systems engineer and get them to give us the real answer...

Why would evry Triumph Tech and the manuals tell you not to use the kill swtich... what would the point be... ??

Until we get a firm answer we are all speaking from the neather region...

duckie · 05-09-2007

Quote:

On 2007-05-09 12:46, JasonS wrote:
Ok, then...

Someone kidnap at put at gun point a Triumph systems engineer and get them to give us the real answer...

Why would evry Triumph Tech and the manuals tell you not to use the kill swtich... what would the point be... ??

Until we get a firm answer we are all speaking from the neather region...

In order: Yes, good point and agreed!