# Garmin Speed/Cadence sensor issue



## Stogaguy (Feb 11, 2006)

My Garmin 500 is not displaying my speed or cadence data on one of my bikes. Works just fine on my LeMond but not on my Cervelo. Both bikes have the GSC 10 speed/cadence sensor. On the Cervelo the "crank" icon is displayed in "menu" mode indicating that the sensor is paired but in "Bike setting" for the Cervelo the "Sensor Details" do not display the Sensor ID number and the sensor is listed as "Not Connected'.

How do I resolve this issue? Thank you in advance for your help.


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## jmorgan (Apr 13, 2012)

Tell it to search in the menu before you go to the sensor screen. Also make sure you press the little button on the cadence sensor and spin the crank (the light on the sensor should blink when the crank passes) until it syncs.


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## simonaway427 (Jul 12, 2010)

You have to pair the sensor on each bike profile.


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## Stogaguy (Feb 11, 2006)

*Firmware issue?*

Garmin's user manual contains the following instructions for pairing the GSC 10:

Select Settings>Bike Settings>[Bike 1]>ANT+Spd/Cad.
Select Yes>Rescan

I cannot follow these directions because the "Rescan" command is not offered when I select "Yes".

Can anyone advise me on this issue? Is this relatedt tot he firmware update that I just did?


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## maximum15 (Feb 6, 2004)

One way (maybe not the most elegant) is to tell the garmin there is no sensor. Then turn it off and back on, and tell it there is a sensor. It will pair then.


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## Stogaguy (Feb 11, 2006)

*Tried that*

I tried exactly what you suggest. I didn't work. I am now proceeding on the hypothesis that the speed/cadence sensor is bad. I put a fresh battery in it. The flashing LED reset procedure confirms that it the sensor is picking up the wheel and crank magnets. However, it appears that the battery dies quickly as the unit will not light the LEDs in reset mode after just a few hours. Even with the fresh battery, the Edge 500 does not detect the presence of the sensor.

I have a new sensor on order and will post when I have a chance to try it.


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## fedrusion (Jul 26, 2010)

I had to replace mine this season, having trouble with cadence and speed dropping in and out, new battery didn't fix the problem. New sensor, re-paired with garmin and its working fine. The garmin should pick up the sensor even if its not paired but if you are in the vicinity of multiple sensors it will default to the closest which caused me issues until I remembered to sync it with mine. (riding next to my friend it was getting confused and would report correctly then occasionally double my cadence unless I dropped away from his side in which case it this problem went away)


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## Stogaguy (Feb 11, 2006)

*Thank you*

Thank you for the input. When working on this issue, I have been careful to banish all other sensors from the garage. 

I have seen the issue with readings from unpaired sensors before. One of my riding buddies picks up my HRM with his Edge 500.


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## Stogaguy (Feb 11, 2006)

*Issue resolved*

My issue was indeed a problem with the sensor itself. Installed a new GSC10 and paired it to my Edge 500 following the instructions from Garmin's website. Problem solved instantly. Thank you everyone for your help.

Here is a link to the pairing instructions
How can I pair my Garmin Speed/Cadence bike sensor (GSC 10) with an Edge 500?


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## Stogaguy (Feb 11, 2006)

*Yes.*

The new sensor pairs just like it is supposed to. I have been for a ride and everything work just fine. Clearly the problem was the old sensor. Somehow it was not functioning correctly.


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## glowingrock (Jun 23, 2013)

The heart rate monitor worked with my Garmin Edge 500 for a while. Then it didn't work. I've bought a new strap, checked the battery, etc. It still won't work. When I try to pair the sensor with the Edge it won't give me the rescan option. It just doesn't show up in the menu (similar to the problem listed above). I've done a master re-set and it doesn't help. I'm frustrated. Any suggestions?


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## cxwrench (Nov 9, 2004)

Go to the Garmin website. Find support number. Call number and helpful Garmin employee will help you figure out the problem. Doesn't that sound easier than posting on a forum (where no one can tell you for what the problem is) and then waiting for a reply?


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## djg21 (Oct 25, 2003)

cxwrench said:


> Go to the Garmin website. Find support number. Call number and helpful Garmin employee will help you figure out the problem. Doesn't that sound easier than posting on a forum (where no one can tell you for what the problem is) and then waiting for a reply?



I've had this same problem twice, and both times Garmin replaced the sensors under warranty. Great customer service.


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## looigi (Nov 24, 2010)

FWIW: There is reset procedure for the GSC-10 and HRM straps themselves. You take the battery out, hold it in place upside down for 10 seconds, and then put it back in. Holding it in upside down shorts together the two battery contacts. (It does not apply reverse voltage because of the way the battery is made and the position of the contacts.) Worth a try if nothing else works.


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## thosj (Mar 24, 2010)

looigi said:


> FWIW: There is reset procedure for the GSC-10 and HRM straps themselves. You take the battery out, hold it in place upside down for 10 seconds, and then put it back in. Holding it in upside down shorts together the two battery contacts. (It does not apply reverse voltage because of the way the battery is made and the position of the contacts.) Worth a try if nothing else works.


Huh, I've never heard this and a quick Google produces nothing. Can anyone confirm this reset procedure? I have a friend with a Garmin heart strap that simply will not work, he went to a Polar ANT+ strap with his Edge 800 after two Garmin straps, the new kind and the old kind. Perhaps this seemingly arcane reset procedure would work?


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## c_h_i_n_a_m_a_n (Mar 3, 2012)

I read it on the Garmin thread of the unconventional reset procedure (upside down battery) and it works for most with problems with the HRM. You could always use some other conductor.


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## cxwrench (Nov 9, 2004)

looigi said:


> FWIW: There is reset procedure for the GSC-10 and HRM straps themselves. You take the battery out, hold it in place upside down for 10 seconds, and then put it back in. Holding it in upside down shorts together the two battery contacts. (It does not apply reverse voltage because of the way the battery is made and the position of the contacts.) *Worth a try if nothing else works.*


Definitely a good tip, and as you said it's worth a go if nothing else works.


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## Hubs (Jun 15, 2013)

When replacing battery in HRM need to leave battery out for at least 1 minute according to Garmin manual . I tried this with several batteries and could not pair my HRM with Garmin Edge 500 . Finally just left battery out walked away had dinner 15 - 20 minutes later re - installed battery and then everything worked .
You need to wait for the HRM to discharge , before putting in a fresh battery.


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## looigi (Nov 24, 2010)

Hubs said:


> When replacing battery in HRM need to leave battery out for at least 1 minute according to Garmin manual . I tried this with several batteries and could not pair my HRM with Garmin Edge 500 . Finally just left battery out walked away had dinner 15 - 20 minutes later re - installed battery and then everything worked .
> You need to wait for the HRM to discharge , before putting in a fresh battery.


Holding the battery in inverted speeds the process and insures the unit is discharged by shorting the battery contacts together.


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## Hubs (Jun 15, 2013)

@looigi , I read your tip now if I remember it in 4 - 6 months . I will try your technique


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## epicrobert (Feb 7, 2014)

*Fixed*

I have just had same problem with new edge 800 onto 2 yr old speed/cad sensors, followed instructions but wouldn't pair.

so set edge to say no sensors.
reset sensor and spun cranks so red/green light flashed.
now set edge to say there are sensors present, and pressed 'search'
paired straight away with both my bikes.


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