Red Light flashing speed sensor 2

Garmin no debe saber cuál es el problema, me cambiaron el sensor en garantía pero ya no funciona igual, fallos continuos en la medición de velocidad, un desastre. Fue evidente que actualizar a la versión 4 quema el sensor, tengo otro que no actualizo y funciona bien, los sensores que envía Garmin en sustitución ninguno está actualizado ni pregunta nunca por la actualización, clara señal de que actualizar es peligroso.

Same problem here.

Can't pair with Edge830, EPIX2 and GCM.

I have inquired to the garmin customer service.
He said the speed sensor cannot be repaired and you should buy new one.

Thus, if the same problem occurs, the speed sensor is just trash anymore.
I have finally bought a third party speed sensor for a quarter of the cost of the original.

PÉSIMO SERVICIO!!!!!! 

Esto me pusieron: 

La garantía de su dispositivo es válida dentro de los Estados Unidos.  Como usted reside en Peru existen las siguientes opciones:

1. Podemos efectuar una orden de intercambio (por otro dispositivo reacondicionado) y enviarle el dispositivo a su país por un costo de $40.00 USD por el envío.  Usted será responsable de enviarnos su dispositivo, a nuestra bodega en Estados Unidos y también por los cargos de aduana e impuestos internacionales al recibir el paquete en su país. Para ello deberá acordar con los términos de exportación que absuelven a Garmin por los cargos de aduana.

Hi ! New to the forum and this is my first post.

I have the same issue with the speed sensor 2 since after the last ride my Garmin 530 tried to update the software of the sensor. It started updating and in the middle of the update it says something like "Sensor not found".. I said "Oh no, it will brick the sensor" and that it was. Now i have sensor which just flashes red every 10 seconds and it is not recognized from any bluetooth device. If you cannot communicate with the sensor, you cannot solve the problem so thats why Garmin will not tell that they gone bad, but that the "problem is known and we are working on update" - NO they cannot solve this trough update.

Thats why i disassembled the sensor and started to detect how it works and what chip is based on. 

Here is some pictures of it:

It is based on N52832 chipset that is multi protocol System on chip (SoC) with 512kB flash and 64kB RAM . It supports Bluetooth low energy that is well known to us ;), so that's why they chose it. Here is it's pinout

From the back, you can find the contacts that Garmin factory can use for easy communicating and program the chip. After a while research and measuring, i found all of the contacts from the back that are used on the chip.

Using serial communication i can communicate with the chip (SWD or JTAG interface).

Now, i am searching a way to find the flash file and maybe solve the problem - OR maybe Garmin will be good enough to share the file to make the upload :) 

If i find a solution, i will call back, or this my work till now maybe will inspire some tech guys to help here

Same issue here. So if they know that the update caused an issue, what are they going to do about it? It looks like they are releasing updates to cause the sensors to fail so that customers will buy new ones so that can have profit. OH MAN!!!

Did you ever get an update from Garmin on this? I have the same issue - flashing red light after update and sensor won't pair with Edge or phone. New battery makes no difference.

Having the same issue — what did Garmin say?

They told me they are looking into it. Nothing more than that yet. They also said I might need to buy a new one which seems a bit off since it was working perfectly until the firmware update.