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Hall Sensor


mshuell

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I'm looking for someone with a 10 year or older oilhead. My R1100RT (code name RiTa) is a 1996 and I've read various stories on this board about the wires deteriorating on the Hall sensor and leaving you stranded in the rain in South Nowhere. For around $200, I can be a new Bosch unit from EuroMoto Electronics. Yeah, I know I can buy the sensors, splice new wires into the connectors, but I want to keep my work to a minimum. The job doesn't look overly difficult, but it doesn't look like fun either.

 

Is this something I should really do? Is there a 100% chance the Hall goes bad or a 2% chance? Does this fall into the category of "If it ain't broke, don't fix it?"

 

Thanks to all, Mark Shuell.

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I think that eventually there will be a near 100% chance of a problem on a high-miles bike.

 

Replacing the harness only will cost very little if you do it yourself so $200 is a lot to throw at the problem, but if you do go that way it is any easy replacement.

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Hall element sensors are used on nearly every car, and have been for many years. They are also used on most bikes. There are tens of millions of them out there, functioning perfectly.

 

Hall sensors have shown themselves to be one of the most reliable parts on a vehicle. When was the last time you heard a reliable report that one failed in a car or bike? My 20-year old K100, my 18 year old Jetta and my 16 year old Jetta, ALL have Bosch Hall sensors (2 of them in the bike). All are original equipment and all work perfectly.

 

The shielded wires used to connect these things do not deteriorate unless they are chafing somewhere. If they ARE poorly routed and chafing, then fix the real problem and protect the wires! Besides, even if the insulation wears through to the ground shield, the sensor will be unaffected. The wire would have to chafe through the outer insulator, then through the shield, then through the center insulator in order to reach the signal wire inside. By then a periodic inspection would have long ago found the problem.

 

From a MTBF (mean time before failure) analysis point of view, your fuel injection (or engine management) "computer" has an orders-of-magnitude greater potential for failure, than a simple Hall sensor.

 

If you check your wiring from time to time to ensure it is OK, you can forget about the Hall sensor.

 

Bob.

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Hall element sensors are used on nearly every car, and have been for many years. They are also used on most bikes. There are tens of millions of them out there, functioning perfectly.

 

Hall sensors have shown themselves to be one of the most reliable parts on a vehicle. When was the last time you heard a reliable report that one failed in a car or bike? My 20-year old K100, my 18 year old Jetta and my 16 year old Jetta, ALL have Bosch Hall sensors (2 of them in the bike). All are original equipment and all work perfectly.

 

The shielded wires used to connect these things do not deteriorate unless they are chafing somewhere. If they ARE poorly routed and chafing, then fix the real problem and protect the wires! Besides, even if the insulation wears through to the ground shield, the sensor will be unaffected. The wire would have to chafe through the outer insulator, then through the shield, then through the center insulator in order to reach the signal wire inside. By then a periodic inspection would have long ago found the problem.

 

From a MTBF (mean time before failure) analysis point of view, your fuel injection (or engine management) "computer" has an orders-of-magnitude greater potential for failure, than a simple Hall sensor.

 

If you check your wiring from time to time to ensure it is OK, you can forget about the Hall sensor.

 

Bob.

 

Whereas all of what you say may be true, the position and materials used on the hall effect sensors on oilhead BMW's have made them prone to failure. A search of these boards over the last two years will show at least 10 documented failures of the HES, if not more. The usual failure mechanism seems to be heating of the insulation (mostly from engine heat) causing hardening and cracks, followed by water ingress to the cracks. This causes either a simple failure until the harness dries or a load-induced failure of the HES itself.

The devices are low-cost, as is silicone insulated wire. If the harness has not failed it would make sense to replace the witr with a high-temperature alternative. If the HES assembly has failed, it is cheap and easy (though time consuming) to replace the devices and harness in one go.

This has become a common enough failure on oilheads, especially earlier models, to be a worthwile prophylactic procedure.

 

Andy thumbsup.gif

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Like Andy said. It's not the hall sensors themselves that are the problem, rather the insulation used in the wiring harness. My guess would be that while the OEM (Bosch) obviously intended this part for use in an under-hood environment they didn't intend the harness to be clamped directly to the block as it is in the oilheads. With this part, in this application, the insulation will eventually fail due to exposure to heat. I and many others have held the failed parts in our hands and there is simply no question about it. Unfortunately you cannot merely check by sight as the problem area is not visible without considerable disassembly. The $20 solution is to replace the wiring with something of an appropriate temperature rating which will provide an effective and permanent fix.

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Whereas all of what you say may be true, the position and materials used on the hall effect sensors on oilhead BMW's have made them prone to failure. A search of these boards over the last two years will show at least 10 documented failures of the HES, if not more. The usual failure mechanism seems to be heating of the insulation (mostly from engine heat) causing hardening and cracks, followed by water ingress to the cracks. This causes either a simple failure until the harness dries or a load-induced failure of the HES itself.

The devices are low-cost, as is silicone insulated wire. If the harness has not failed it would make sense to replace the witr with a high-temperature alternative. If the HES assembly has failed, it is cheap and easy (though time consuming) to replace the devices and harness in one go.

This has become a common enough failure on oilheads, especially earlier models, to be a worthwile prophylactic procedure.

Interesting. Looking at the sensors themselves on my old K100Rt, they are exactly the same Bosch sensor as is used on my 2 Jettas. As mentioned, none of these have given me any trouble.

 

But the extra heat that an oilhead encounters may be what is creating problems. It sounds like it is the wires, and not the sensor itself that is prone to shorts.

 

As you say, silicone insulated wire (or any high temperature wire such as hypalon) will help there. Also, applying heatshrink on exposed areas is an suggestion to give added armor.

 

Bob.

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It sounds like it is the wires, and not the sensor itself that is prone to shorts.
Why yes, you may be on to something there. grin.gif
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It sounds like it is the wires, and not the sensor itself that is prone to shorts.
Why yes, you may be on to something there. grin.gif

Oh yes, one more thing. Did I mention that the wires might be suspect? grin.gif

 

Bob.

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  • 1 year later...

All of this discussion is very interesting to me. I have a recently purchased 2000 R1100RT that had just rolled 50200 miles and the engine died after about 100 miles of downpouring rain. Diagnosis--bad Hall Sensor Plate. My bill for the 4 day wait on part was right at $800--don't want to do that again. Put the bike on the side stand and stood off the road under trees with my arms crossed thinking, "You ain't supposed to do that--that's what Harleys do!"

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Is this something I should really do? Is there a 100% chance the Hall goes bad or a 2% chance? Does this fall into the category of "If it ain't broke, don't fix it?"

I will take a minority position on this and recommend the "If it ain't broke, don't fix it". My 1999 RT had about 90,000 miles on the clock. A few months ago, following stuff I read here, I decided to take the Hall Effect Sensor out and look at the wires. I removed it, split the outer cover on the wires and examined the wires. They were fine and showed no sign of cracking or brittleness. Yours could be the same, or they could be about to crumble and short. You pays your money and you takes your chances.

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Is this something I should really do? Is there a 100% chance the Hall goes bad or a 2% chance? Does this fall into the category of "If it ain't broke, don't fix it?"
I'll fall somewhere in between. I'm not an advocate of replacing parts just because I read somewhere one on my bike may fail some day.

 

But on the 1100s brittle wire on the HAL has been common enough that I do think that every 30K or something it's worth an inspection. Pulk the HAL ass'y, it doesn't take that long, and have a look. If the wires are starting to crumble, well then you know what to do. OTOH if all is well, put it back and take another look in another 30K.

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But on the 1100s brittle wire on the HAL has been common enough that I do think that every 30K or something it's worth an inspection. Pulk the HAL ass'y, it doesn't take that long, and have a look. If the wires are starting to crumble, well then you know what to do. OTOH if all is well, put it back and take another look in another 30K.
Trouble is that you can't really do an easy visual inspection for this problem. The primary problem area is under the clamp that holds the HES harness cable to the plate, and this area is covered by shrink tubing. You usually need to cut the tubing off in order to detect the problem, and once you've done this you've done 90% of the work required to replace the wires with something with a proper high-temp rating... so you might as well go and get it over with. Once you've upgraded the harness wiring you'll never have to think about it again.
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Trouble is that you can't really do an easy visual inspection for this problem. The primary problem area is under the clamp that holds the HES harness cable to the plate, and this area is covered by shrink tubing. You usually need to cut the tubing off in order to detect the problem, and once you've done this you've done 90% of the work required to replace the wires with something with a proper high-temp rating... so you might as well go and get it over with. Once you've upgraded the harness wiring you'll never have to think about it again.

 

I concur. You have to cut the tubing open to inspect the wires. At that point, if the wires are good, you have two choices: either replace them which requires soldering in new wires; or, taping them up with some hot seal tape (I forget the correct name). Neither will be as clean as the original installation.

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With 78k on my RT, I guess I might as well put together the materials needed to upgrade the wiring. That way, next time I do my 6k sync, I'll just go ahead and make the most of having things apart. Which leads me to the question:

 

Anyone found an easy-to-find source for the wire? I read the suggestions mentioned in the article by Dana E. Hager, and will use those, but I'm open to other options.

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Anyone found an easy-to-find source for the wire?
It's not hard to find, here's one good source. Or you can PM bmwmick (on this forum) who has completed harnesses available.

 

Just what I was looking for. Thanks. thumbsup.gif

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With 78k on my RT, I guess I might as well put together the materials needed to upgrade the wiring. That way, next time I do my 6k sync, I'll just go ahead and make the most of having things apart. Which leads me to the question:

 

Anyone found an easy-to-find source for the wire? I read the suggestions mentioned in the article by Dana E. Hager, and will use those, but I'm open to other options.

 

WOW,

Nicely resurrected thread. smile.gif

 

Ed,

I sent you a PM.

 

Mick

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