WTH? Bike Only Starts in N

[BikerMiker]

Hi all.... been a while since I posted here but... I'm stumped!

Bike only starts in N. I thought this was going to be an easy clean and fix or a
replacement but.... NOPE! It started as an intermittent issue that has now become
permanent.

Clutch switch is ok.

Bypassing the clutch switch doesn't help. 12v is on the hot side when ignition is on .

Traced the wiring and both conductors ring out all the way to ECU.

Tried a spare ECU I have laying around and no difference.

I have the kickstand safety switch bypassed already.

I used the pic of the wiring diagram linked below as a reference.

https://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/530846-wiring-harness-info-needed.html#post5233271

I'm am out of ideas!!

[sgoodwin]

Just an FYI, I've had clutch switches on both my 11S & 12GS that would click & test ok but weren't good. As soon as current was applied they failed. It's not too expensive to just replace it. I took one apart & discovered the contacts from the switch to the pins for the plug only touch, no solder or crimp of any kind. Cheesy crap!

[BikerMiker]

Originally Posted by sgoodwin

Just an FYI, I've had clutch switches on both my 11S & 12GS that would click & test ok but weren't good. As soon as current was applied they failed. It's not too expensive to just replace it. I took one apart & discovered the contacts from the switch to the pins for the plug only touch, no solder or crimp of any kind. Cheesy crap!

What is so weird is that I am bypassing the switch, with jumper, and it is still not working. I'm at a loss ATM.

[BikerMiker]

Just tore it apart again.

Checked and cleaned all the connections at the ECU.
Reverified that there's not a short or open in the harness between the ECU and the switch location.
Still getting 12v on hot when ignition is on at the switch plug.
Shorted pre switch with a jumper at the plug and tried without one in case it was normally open.

Is there some other logic that involves the neutral switch?

[sgoodwin]

I did that on my '12 GS & after a couple starts the electronic nanny said no more as it didn't detect the switch switching. Never tried it on the 11S so no idea if it is different that way.

[wswartzwel]

Does kickstand up make a difference

[BikerMiker]

Originally Posted by wswartzwel

Does kickstand up make a difference

No. I made a bypass plug mod years ago to consistently give the kickstand up signal. I
did have it in my bag in case I needed it while riding but I decided just to put it on
instead of waiting for an inopertune moment for it to fail. I did unplug it during testing
yesterday and putting the bike in gear kills the engine while it's removed.

[BikerMiker]

Originally Posted by sgoodwin

I did that on my '12 GS & after a couple starts the electronic nanny said no more as it didn't detect the switch switching. Never tried it on the 11S so no idea if it is different that way.

So what you are saying is; you bypassed the switch, but after a while the bypass failed to work too, the final fix was a new switch?

[njsax]

Maybe it's the Neutral Safety Switch in the gearbox. They get gummed up over time. Try flushing out the gearbox with some kerosene or remove the switch and clean it.

The MAX BMW Parts Fiche calls it the "Idle Switch", and it's located at the lower rear of the gearbox housing. See Diagram 23_0760, item 16.

[BikerMiker]

Originally Posted by njsax

Maybe it's the Neutral Safety Switch in the gearbox. They get gummed up over time. Try flushing out the gearbox with some kerosene or remove the switch and clean it.

The MAX BMW Parts Fiche calls it the "Idle Switch", and it's located at the lower rear of the gearbox housing. See Diagram 23_0760, item 16.

That switch seems to be working as it still starts in N and the bike "knows" when it is neutral.

I'm beginning to think there might be a dependency at or before the ECU that is not being met that is affecting it. It was intermittent at first so.... That's a clue that there is most likely an open / short somewhere, just not where you would expect.

[sgoodwin]

Originally Posted by BikerMiker

So what you are saying is; you bypassed the switch, but after a while the bypass failed to work too, the final fix was a new switch?

Yes, but it did start a couple times before it didn't anymore.. Checked & had a code for the failed switch. I'd try a switch then if no go it's track down the wiring short more than likely, so fun.

[Jozef Schumann]

GS 911 scan tool. Scans all control modules (engine, immobilizer, etc.) for stored fault codes and you'll get a detailed description for each code, pointing directly to a failed component.

J.S.

[sgoodwin]

Yep. invaluable tool for these bikes.

[BikerMiker]

Originally Posted by sgoodwin

Yes, but it did start a couple times before it didn't anymore.. Checked & had a code for the failed switch. I'd try a switch then if no go it's track down the wiring short more than likely, so fun.

I don't think I need to try a switch, it doesn't work even when the switch is bypassed with a jumper.

I plugged the kickstand back in and that all works as it should too.

I'm going to take all the plastics off and really probe all parts of all the harnesses.

Anyone have a GS911 laying around they want to part with?

Someone else suggested trying dead shorting the hot side of the switch. I did notice that when ignition is on,
resistance increases between ground and the pin that receives the hot signal on the ECU.
That doesn't make sense to me really, but maybe they weren't explaining it well.

[wswartzwel]

Check the ground wires from the battery that attach to the frame near the battery. they sometimes corrode there. could be losing connection to ground. I would also check the heavy ground cable frame connection as well

[BikerMiker]

Originally Posted by wswartzwel

Check the ground wires from the battery that attach to the frame near the battery. they sometimes corrode there. could be losing connection to ground. I would also check the heavy ground cable frame connection as well

Thanks. That makes sense, I'll check that too.

[BikerMiker]

This morning I cleaned the ground-to-frame point. It looked good but did it anyway.

No luck, no change.

I took it out for a ride today anyway, first one since doing all the toubleshooting. Got gas and then
went to start the bike, pulling in the clutch without thinking and it started while in gear.

Met up with a friend, stopped multiple times during the ride and it worked fine all day.

I have theories but no clear idea how or why it started working again.