Has my ECU / BMS died?

Aus23 said:

hogfarmer - great news albeit I'm deeply jealous!

Squibb - I think I shorted out the side stand switch at the plug (joined 2 of the 3 wires (not the red one from memory)). Clutch switch ... any clues as to what to do/look at with this one.

I also have just checked that there's 12+V at the BMS relay going in to it, and then out of it.

Should I buy some replacement relays just to check?

Aghhhhhhhhhhhh!

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If you check the diagrams from the link in post 10, page 4 it clearly shows the correct scenario - it's a complex system, linking the live from the ignition to the neutral light switch from the gearbox, to the clutch, sidestand & kill switch. A failure in any one of these elements could kill the ignition. The clutch switch is just a case of removal & jump the leads to give the appearance of the clutch lever being actuated/pulled back to the bars. However, my money is on the sidestand switch, which is more complicated than it first appears & prone to internal corrosion.

Incidentally, were there any issues historically, when the bike was in use regularly?

squibb - many thanks. There were no issues at all with the bike, it's been perfect. I'll re-look at the side-stand switch - am I right in thinking that if I short it out at the plug (on the right hand side of the engine), that will bypass it, or is there more to do than that? Clutch switch, again, I'll go and look. I'm guessing that you're suggesting it's more likely to be these switches than a BMS failure?

Aus23 said:

squibb - many thanks. There were no issues at all with the bike, it's been perfect. I'll re-look at the side-stand switch - am I right in thinking that if I short it out at the plug (on the right hand side of the engine), that will bypass it, or is there more to do than that? Clutch switch, again, I'll go and look. I'm guessing that you're suggesting it's more likely to be these switches than a BMS failure?

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No ... the issue could be anywhere & it's important to keep an open mind. I am just steering you towards what I think is the most likely culprit. I didnt look at the bypass method, as the wiring colour you mentioned did not match the diagram. So, just in case someone has meddled previously, I would suggest you get in there with a meter & check out each wire back to the relay intially. Then check to see what happens at the relay when the sidestand is deployed - if we are looking in the right place, your relay thinks the sidestand is in the down position all the time. If that doesn't reveal anything, then look at each component in that interlocking system that serves to kill the ignition/fuel supply - they are all there on the diagram, as I listed in post 21. You need to tie down what precisely is stopping power getting to the ECU/fuel/ignition/lights, yet still supplies the starter motor. Switch corrosion on a bike that has been laid up seems the most likely if all the fuses/relays check out. The neg/earth continuity issue at each component can checked with your meter & can be quickly repaired for testing purposes by just running fresh leads from the battery neg terminal should a problem emerge. Keep everything methodical & the problem will reveal itself.

Finally, I don't recall whether the bike has an Alarm/Immobiliser fitted. Old/aftemarket jobs are notorious for creating probs due to poor installation &, well, just age.

Good Luck ................ KEN

Hold on a wee minute The Clutch switch and Sidestand switch should only become an issue of the Neutral light is not illuminated Its at that stage that the ECU thinks that the stand is down and the bike is NOT in neutral and cuts ignition

Whilst I can but agree Dr , the OP has to start somehwere & this seemd the most likely given the circumstances - then, as I said, there is the neutral switch, kill switch & ignition switch to follow through. He has the wiring diagrams, so it has to be a case of methodically checking/testing.

However, all this led me to recall a mates old VFR800 a couple of year back - pretty much the same issues as we have here. Unbenown to him, a previous owner had an Alarm/Imob installed, must have been years back, with the control unit tucked away completely out of sight. All was well, all the time he wasn't aware the thing was there, as he didn't aquire a remote with the bike. However with hindsight the small led on the dash should have given a clue, but he thought this was just for show, as it wasn't wired up. Then, parked up for the winter, the battery fell over - installing a new battery in Spring somehow awoke the hidden alarm & whilst no sounder operated, the indicators flashed a few times & the bike's systems were dead. Removing all the rear bodywork revealed the control unit, so we simply removed the thing & stripped out the appalling wiring - reconnected the battery & everything was fine. Just a passing thought to consider.

Okay so what is wrong here is that a basic route of diagnosis has not been followed!

Issue = Bike will not run

What changes were made prior to this problem = New Battery

Did Bike run after fitting Yes it Did but only for a short period Plug flooded and now U/S??

NOTE :- Should the temp light come on when you turn the ignition to the on position?

Both the temp light and the oil light should come on on the GS and CS, (the temp light for 3 - 5 seconds then the temp light should go out). Not forgetting the neutral light if the bike's in neutral. Trevor#999
On a FI GS/CS the temp light will not come on when you turn on the ignition if the bike's side stand is down and you are in gear (unless you pull in the clutch lever).

ALSO The ECU / FI unit / BMS-C must have enough power to begin with. In otherwords if the dash lights do not come on in their normal sequence when you turn the key on, you either have a busted fuse or there is not enough power for the ECU. Have you checked the fuses?


My thoughts are that you stopped the bike before it got to optimum temperature and the spark plug has got soaked and basically that has killed it I am not sure if the whole coolant light thing is a red herring or not

But before you go changing stuff about Check the above points and come back to us!

DrF and Squibb - really appreciate your input. It's great to get some pointers and support when the bike's stuck in a garage and I'm struggling. OK, will tomorrow endeavour to check switches (clutch/side stand/kill) and then also pull the spark plug, check if it is corroded/flooded etc. Again, thanks for the help, it's very welcome.

Morning! Spark plug all OK. With the clutch, if I put it in gear, neutral light goes out, it won't crank, pull in clutch, cranks fine in gear.

Aus23 said:

Morning! Spark plug all OK. With the clutch, if I put it in gear, neutral light goes out, it won't crank, pull in clutch, cranks fine in gear.

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As we thought previously, no sparks & no fuel pump. Seems like the neutral telltale switch in the gearbox & the clutch switch are both OK then. Where have you got to with checking the side-stand/relay scenario? Just leave the original wiring alone & concentrate on what the prop stand switch is telling the relay. Seems like the prop stand or kill switches could be suspicious.

After my PITA story about hidden alarms/immobs you don't mention whether this possibility has been checked out?? OK, I know it's a long shot, but it happens &, like second keys, remotes & alarm certs get lost as owner changes build up through the years. Somebody breaks the remote, or it drops off the key ring, so they just leave the control box hidden somewhere, alarm not set, & pass the bike on to the next owner. Did the indicators flash or did anything unexpected occur when you shut the bike down after fitting the new battery that could suggest an alarm auto-setting? Maybe 30-60 seconds after you turned off the ignition?

Again, good luck tracking this down .................... KEN

Sorted - BMS replaced. All perfect, now we need some sunny weather and I can enjoy the roads of Northern Ireland!

Good news, you can regrow your hair now.