Gearbox position sensor malfunction

[stevencovert]

There was a post talking about Magic Mirror magnets...VERY powerful. Some were using 2 of 3 magnets on the mirrors, opting to use the existing guide pin. It was suggested using the unused magnets on the oil filter. So close to the gear sensor, destroyed it. This may have nothing to do with you, but it's always good to know.

I would disagree. The GBPS is simply a potentiometer. Any dirt or moisture will give false readings. I believe the same part is on both 998 and 1330. A pot is a mechanical device that changes resistance. I wouldn't believe anything can interfere - magnets, RF, etc. On my 998 the part was simply worn - the bushings are junk plastic. It actually rattled when I took it off. Would love to see an aftermarket with a metal bushing & hermetically sealed! High failure rates on this part.

Incidentally some people found replacing the +/-/R switch assembly worked for them with random gear problems. Here, the switches in the part ARE super sealed! I replaced mine out of frustration (ongoing on the 998!) with it getting stuck in a gear or popping into Neutral and staying there. The connector is right at the nose of the bike behind the black cowling, and I can see it getting dampness and grime on it easily. After replacing mine with no luck, I read more that simply pulling the connector and spraying it with some alcohol might be more the problem than the switches themselves. On my old unit I definitely can still hear the strong clicks on all switches. Spraying them will do nothing BTW, being sealed. This makes me think that simply pulling and reconnecting the plug to clean it up a bit is what actually is fixing those issues. I even ran a test where I pushed and held the + or - running down the road for a mile or so. Any bad connection (IMHO) would have caused a gear change (?) but nothing happened. I changed it anyways - wasted $100!


Steve

[billybovine]

I would disagree. The GBPS is simply a potentiometer. Any dirt or moisture will give false readings. I believe the same part is on both 998 and 1330. A pot is a mechanical device that changes resistance. I wouldn't believe anything can interfere - magnets, RF, etc. On my 998 the part was simply worn - the bushings are junk plastic. It actually rattled when I took it off. Would love to see an aftermarket with a metal bushing & hermetically sealed! High failure rates on this part.

Incidentally some people found replacing the +/-/R switch assembly worked for them with random gear problems. Here, the switches in the part ARE super sealed! I replaced mine out of frustration (ongoing on the 998!) with it getting stuck in a gear or popping into Neutral and staying there. The connector is right at the nose of the bike behind the black cowling, and I can see it getting dampness and grime on it easily. After replacing mine with no luck, I read more that simply pulling the connector and spraying it with some alcohol might be more the problem than the switches themselves. On my old unit I definitely can still hear the strong clicks on all switches. Spraying them will do nothing BTW, being sealed. This makes me think that simply pulling and reconnecting the plug to clean it up a bit is what actually is fixing those issues. I even ran a test where I pushed and held the + or - running down the road for a mile or so. Any bad connection (IMHO) would have caused a gear change (?) but nothing happened. I changed it anyways - wasted $100!


Steve

The GBPS is not a simple potentiometer. It is a hall effect transducer. That works by changes in the magnetic field.

[Big Mac]

The GBPS is not a simple potentiometer.

I agree. I took our GPS off a few days ago and measured the resistance between the 3 pins — it didn't behave anything like a potentiometer.

[stevencovert]

Well that might explain some things! Guess I better check for myself rather than my local tech

[Big Mac]

The schematic for the bike confirms that the GBPS is indeed a Hall Effect Transducer (https://www.electronics-tutorials.ws...ll-effect.html). If I still had it off the bike I guess I would test it by applying a voltage to pins 1 & 3 and then sensing the voltage at pin 2 while turning the spindle? Or is the magnet in the gearbox?
gbps.jpg