2015 GEM eS Speedometer issue

I have a 2015 GEM eS with a speedometer issue. I was getting codes 82 & 81. I replaced the speed sensor and magnet on the GE 7hp motor. The error codes went away after replacing the magnet twice. The odometer seems fine but the speedometer is not accurate. It reads about 1/2 the mph. When I put the speedometer in KM/h it appears about the same as the mph. I recently put a magic magnet on the car that I purchased from David Bissen. My max speed instantly increased to 30+ mph from the prior 26mph per my gps speedometer app. The car’s speedometer still reads the same.

The flow of this is very confusing.

When EXACTLY did the speedo become inaccurate? Are you saying there was still an issue after you replaced the sensor the second time and your codes cleared? (before adding the MM?)

All was ok until you added the MM and the speed readin goes to appox half? This is perfectly normal and the very nature on how it works.

Yes, When running the MM in place the suggested work-around is to switch the display to KPH and the number displayed comes close to a MPH reading when compared to GPS.

The issue started before i added the mm. I thought the mm might correct the speedometer issue but the results are the same.

I think you misunderstand the purpose and what the MM does. It removes pulses, not adds them. The fewer the pulses, the slower the reading on your speedo. If your speedo is slow to begin with then the MM will not help.

K- Remove the MM. How far off is the speedo?(compared to GPS)

How fast does the car go without the MM installed?

I wanted to increase my speed so I purchased the mm. I thought as a side benefit it might correct my speedometer issue. According to my gps app the car would go 26mph before the mm. The car speedometer would show roughly half speed. The car does 31+ mph now per the gps app. The car speedometer indicates roughly half speed in mph & kph with or without the mm.

Impossible right?
Speedometer works. Ie. changes with speed of the car.
Yet is not affected by kph/mph or magic magnet.

I got a sensor and magnet from NEV and the magnet was marked “4 pole” and it now reads 1/2 the actual speed. Tried for several weeks to call them and always got recordings so I left messages. No return calls and now at that same # I get GEM and they don’t seem to kno
w who NEV is and refer me to my local dealer.

NEV is actually The Thing Shop. Cant remember if they have different phone numbers or not


The mph & kph read roughly the same (half speed) with & without the MM on the speedometer. When the car was running before the 81 & 82 errors, the speedometer would indicate 26 mph before the governor stopped the acceleration. With the MM I have clocked 30.6 mph (gps app) before I let off the pedal. I feel that the speed magnet and/or the speed sensor have caused this problem, I hate to buy them again since the error codes have gone but I do want an accurate speedometer.

I purchased another speed sensor from Amazon. It was a Clubrally brand. It appears to have eliminated the error codes 81 & 82. I changed the speedometer from mph to kph. Now the speedometer aligns with the gps app on my phone.

There you go.
I assume you also put the MM back inline?

For future readers, do you have a link to the Amazon product that you bought?
(this works as long as the seller does not disappear)

I did hook up the mm again.

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