GRiSO won't start, displays "ECU" and a plug icon

Hey people,

My GRiSO won't start today and I don't know where the issue is.

When turning the key:
- LED lights are powering on on the dashboard
- needle from the speedometer is going up and down as usual
- then all LED lights from the dashboard are powering off except the "fuel reserve" LED
- side stand LED goes off
- neutral LED goes off as well
- dashboard displays a "ECU" + some kind of unplugged plug.
- no fuel pump noise
- blinkers, headlight, license plate lights are working normally
- engine won't start, not a single noise coming out of the bike when trying ignition

I recently made some changes on the motorcycle, but didn't touch the ECU (I don't even know where it is located...):
- I removed the indicators at the front. They were aftermarket LED indicators soldered to the wires, I cut them, soldered new connectors and plugged new indicators from Rizoma.
- I removed the original license plate holder completely, and replaced it with the one from Officine08 which is directly screwed to the rear brake caliper.
- I removed the indicators at the reat, they were also aftermarket LED indicators soldered to the wires. Same there, I cut them, soldered new connectors and plugged new indicators from Rizoma.
- I plugged the license plate light back in because I thought the error was coming from there, but doesn't change anything.

Any help would be greatly appreciated, my tech level is very low.

When installing the licence plate holder have you trapped the speedometer sensor wire under the bracket or bolts when tightening them down? If you have you may of exposed the wires and shorted it out. This will blow the fuse which also supplies power to the ecu leading to the ECU unplugged icon on the dash.

From memory it's either the rearmost or second rearmost fuse, a 15A, in the fuse box. If it has blown? Unplug the speedo sensor, (Right hand side under the seat behind the footrest hanger plate.) replace the fuse and see if it runs. If it does then you've damaged the speed sensor. Replace it and make sure you don't nip the cable on the new one.

Pete, thanks so much.
You're right, I damaged the speed sensor while tightening the rear plate holder and the fuse is blown.

I'll replace the fuse tomorrow and test if it runs with the speed sensor disconnected, and I'll order a new one anyway since it's visibly damaged.

Thanks a lot!

I did exactly the same thing on my old bus last year. That's how I guessed it.

Oh, and when unplugging the speedo sensor make sure you disconnect the right plug. There are two close to each other under the RH footrest hanger plate. The other one is the rear brake light switch plug. From memory the speedo connector has three wires/pins. The brake light only two.

Those plugs are beside the airbox, on the RH side under the seat, right?

Well I think I disconnected the right plug (was mainly focusing on the wire thickness, the speedo sensor is quite thin, the other one I found was thicker than the cable coming out of the speedo sensor). If I'm correct, that was the 2-pin connector.

At least, I disconnected it, changed the fuse and now the engine starts again, with no error on the dashboard.

I'll order a new speed sensor tonight, and I hope it's not too much of a pain to change?

I'm heartily sick of giving the godlike Pete street cred. So, I haven't. He is such a fucking star that he is beyond the need for it.

True enough, but don't you feel just a bit sorry for him, having to live up to the high standards he's set? The rest of us have the luxury of crawling along like slugs because, well, we are.

Truthfully, it's folks like him that brought me here, and keep me coming for more. My GRiSO rides, and runs, much better than new because of the sage advice I've gleaned from this crew.

Papa Lazarou wrote:

I'm heartily sick of giving the godlike Pete street cred. So, I haven't. He is such a fucking star that he is beyond the need for it.

Yep. And entertaining to boot!

All I have is a good memory for problems and their solutions. I've also made the CARC bikes my muse for the last fifteen years so I've probably seen most of the 'Issues' they are likely to exhibit. I'm really nothing special. Michael is a much better mechanic than I'll ever be.

I appreciate your modesty Pete. But without your considerable efforts and excellent guidance, l would have given up on my GRiSO long ago. You have enabled amateur mechanics the world over to live with these bikes long term. There is clearly nobody who has done more to support the brand and owners of its bikes. Mandello ought to give you the key to the city.

I'm wondering something: what is the use of this sensor I unplugged?

Because, I thought it would be the part allowing the ECU to know how fast the motorcycle goes. Except that since I unplugged it, I still have the speed displayed on my dashboard. Sorry for the noob question...

Have you ridden it? The speed still shows. It shows as '0', even if you're bouncing it off the rev limiter in fifth!

Nope, I've ridden it and the speed still shows normally. Did I disconnect something else? The fuse didn't blow again though...

Well perhaps you unplugged the tail light, but that shouldn't blow the 15A fuse.

If Pete was truly a god then he'd relocate to the Pacific Northwest so we'd have his expertise here. I would suggest the Portland area.

I am thinking Brisbane after all he is ours we saw him first

He can live wherever he wants as long as he keeps posting to the GRiSO Ghetto!

Pete Roper wrote:

Oh, and when unplugging the speedo sensor make sure you disconnect the right plug. There are two close to each other under the RH footrest hanger plate. The other one is the rear brake light switch plug. From memory the speedo connector has three wires/pins. The brake light only two.

Axael wrote:

Those plugs are beside the airbox, on the RH side under the seat, right?

I think you probably unplugged the wrong plug. The one Pete refers to is indeed under the RH footrest hanger plate, and a little hard to reach. It is not beside the airbox. You might look one more time.

Moto