What happens when the gear position switch fails

[Feltwell]

Not used the GS much since I came back from the TT. Went to take it for it’s MOT today – strange, gear indicator isn’t working.

Got part way there and the bike was really playing up – go to pull away from lights and at about 5mph suddenly there would be no throttle at all, worse still was it would cut back in with no warning and with little relation to the twist grip position! Sometimes it would be OK, sometimes it would play up. Nursed it to the MOT place, it passed (!). Riding it home through rush hour traffic was just horrible – throttle would stick on, throttle would stick off, finally found that you could pull away in first to about 5mph, then change into 4th and slip the clutch like mad and it would behave, most of the time. A bit interesting trying to turn right across busy traffic with no idea if the throttle would respond or not…….

It seems that the gear position indicator switch is a known fault on older GS's, but I don't see much for the LC models. From my bike it appears if the ECU doesn’t know what gear it’s in it sends the whole bike screwy. Why do they have to make them so bloody complicated now? If I'd had far to go it would have been a recovery job, the bike was dangerous to ride.

Put the GS911 on the bike and the only repeating fault code was for the gear position indicator switch.

So, came to take it off. The switch is on the back of the gearbox, just up behind the gear lever - dead easy to get to, 2 screws to remove, no strip down required. At least that's what I thought until I realised the connector was nowhere to be seen. Haynes manual says you have to remove the starter motor to get to it, and they're right, and that is a right pain as the rear fixing bolt for it is very difficult to get to with the swingarm in place. It is possible to do it without removing the swing arm but it's damn tight and requires the right tools! What a bad design. No way could I have disconnected it without removing the starter motor first, then I found it was cable tied tightly in place behind the connector as well.

Got the switch off and it's let moisture and dirt in past it's O ring so I'm confident it's failed. I'd recommend taking it off - as without disconnecting it is literally a 2 minute job - and putting some silicone grease around the O ring prior to refitting, make sure no moisture can get past it. If anyone wants a picture of where it is I'll post one up, but it's easy to find.

New switch on order - £105 from Moto Works, but I got a new old stock one off Ebay for £70. Hopefully that will sort it.

 

[Onahi]

Other than the Faff of getting to the areas, It sounds a good result. A good advert for the GS-911 too.

 

[Joca]

I got mine from BMW. It was virtually the same price.

Sent from my M2007J22G using Tapatalk

 

[Feltwell]

I got mine from BMW. It was virtually the same price.

Sent from my M2007J22G using Tapatalk

I tend to go mail order simply because it's an hour's round trip to the nearest BMW dealer. Usually I use MotoWorks, always had good service from them.

 

[CPJS]

I tend to go mail order simply because it's an hour's round trip to the nearest BMW dealer. Usually I use MotoWorks, always had good service from them.

When ever I get something from the dealer I ask them to post it to me, which they do at no extra cost.

 

[Neil W]

Alternatively any bmw car dealership can supply motorrad parts if you know the part number

 

[Pukmeister]

Why not try washing out the old switch with a good squirt of electrical contact cleaner then put it in the airing cupboard overnight.

 

[The Other PaulG]

Well done for posting that, it's very likely that others will experience a similar issue and that write up will be valuable.

 

[Deleted account 221212001]

I’m equally interested in how the GS passed its MOT if it was horrible to ride and the throttle was sticking on, then cutting out at 5mph, that doesn’t sound like a road worthy motor vehicle to me!

 

[Feltwell]

Useful to know about posting parts and the car dealerships, thank you.

Salvaging the old switch - not really an option, it's completely sealed all around it's perimeter in manufacture - I very much doubt you could get it apart without destroying it. It's *such* a monumental pain in the arse to get to the connector, you also want whatever goes back on to last as long as possible! If it's the same as the older GS models then it isn't a potentiometer, it's just a rotary switch with contacts that will wear, especially if muck has been getting in - better to replace it with a new'un and have done with.

Daft thing is, a quick smear of silicone grease on that O ring and it would have been good for the life of the bike! Hence why I'd strongly encourage everyone to do that as a preventative measure - will take 2 minutes to do. Why silicone grease? It's fairly thick and waterproof, so it won't wash out, and being purely silicone based it won't affect the O ring, no matter what it's made from. Use anything oil based and (depending on what the O ring is made from) it may cause it to swell and perish. I'll put a picture up here when I fit the new switch.

The MOT - no, it wasn't road worthy! But they don't ride the bike at the MOT, and it started and idled no problem, even blipping the throttle got a response - so the tester would not have been aware. Beyond limping it home there was no way I was going to ride it again until it was fixed! If I'd known there was a problem before I took it for the MOT I would have postponed it until I'd fixed it.

 

[Joca]

I think I opened mine and cleaned it with contact cleaner.. The contacts were wuute worn and didn't last.

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[GSBruce]

YouTuber “zooskifilms” shows the starter removal and it is very tight as Feltwell reports.

https://youtu.be/ohE3-4szb50

Better to grease the switch o-ring now and hopefully avoid pulling the starter later.

 

[Feltwell]

YouTuber “zooskifilms” shows the starter removal and it is very tight as Feltwell reports.

https://youtu.be/ohE3-4szb50

Better to grease the switch o-ring now and hopefully avoid pulling the starter later.

Yeah, for the starter motor it's getting the rear of the two fixing bolts in and out that's the really fiddly bit. It is possible to do without removing the swing arm but it's very very tight and you need the right tools, specifically a very long and thin T30 torx bit, not just a Torx bit on an extension. You will not be able to unplug the switch without removing the starter, such a stupid design!

Anyhow - my bike is fixed, put the new switch on yesterday, cleared the 91 instances of the fault that had come up on a circa 5 mile ride to and from the MOT station - no wonder it confused the crap out of the ECU! Took the bike for a ride today, all is good and no fault codes.

For the sake of a 2 minute job, I'd really recommend taking this switch off and putting a bit of clear silicone grease around the O ring - just to ensure water is kept out. Water had definitely got into mine, the little shaft that comes out of the gearbox was corroded.

For anyone who's not sure how to do this:-

The switch is on the back of the gearbox low down, behind the left hand rider's peg. Lay on the ground and you'll see it, no need to strip anything down. The switch looks like this:-



And it lives here:-



Take the two torx screws out, pull the switch off, clean up the surround it mounts onto:-



Flip the switch round, give it a clean - try not to disturb the position of the central cross piece, makes refitting it much easier. If you do disturb it then this picture shows it in the right position if the gearbox is in neutral. Smear some silicone grease around the green O ring and refit it.