Garmin HRM not pairing with PM5

[Oldcolonial]

I am having difficulty with my Garmin HRM connecting to my PM5. It is a relatively recent problem, perhaps one that showed up when I got a new Garmin watch ( Fenix 6 ). Note, I did not replace the HRM strap or transmitter. I have confirmed that the strap works though as it pairs nicely with my new watch. the Garmin is the Garmin Dual transmitter (See below).
https://www.garmin.com/en-US/p/649059

Symptoms are that I can see the HR strap/transmitter ID flash up on the PM screen for just an instant before it disappears ( before I can select it!). It turns out that sometimes, on rare occasions, I get it just right and it does get paired. It is almost like it is paired to another device. I tried turning off the blue tooth on both my phone (ergData not runnng either) and the watch itself as well to see if that matters. It did not seem too.

I think the software on my PM5 may be out of date as the erg data app tells me I need to update the software on my PM5. I have a USB A to B chord coming so that I can do this. I tried doing the update with a USB drive and that did not work.

Love to hear if there is a fix for this.

[JaapvanE]

I suspect that the Garmin watch "claims" the strap, and as it has a limit number of connections, it will not be able to serve the PM5. Try disabling BLE sensors on your watch before the row and see what happens.

[Oldcolonial]

Hi Jaap;

Thx for the advice. I gave it a shot with the watch completely out of the picture and still the problem persists. I turned the watch off completely and still the problem persists. Same with both the watch and the phone completely off.

Next, I will try replacing the battery in the transmitter. Maybe it has enough power for the watch and phone to work but not enough for the PM5.

[Tsnor]

Bluetooth is a 1 to 1 pairing. If there is a race condition to pair with the belt the slower PM5 will lose every time.

ANT+ is a broadcast anything can listen to. Your PM5 should be able to see your belt ANT+ HR broadcast even with other devices paired.

Suggest you put on the belt. Pair the belt over bluetooth with your phone. See you heart rate on the phone. That way you know the belt is active and works.

Then goto the "connect HR monitor" panel on the PM5 and wait and see if the ANT+ entry shows up from your belt. If it doesn't you have a problem with your belt or your PM5 or 2.4ghz interference. Since the belt worked to your phone, suspect the PM5. It can take 20-30 seconds for the ANT+ signal to be recognized, but it shouldn't take minutes. Removing the batteries from the PM5, waiting a few mins, and replacing them is one way to soft reset your pm5.

(if your belt has an app that controls the radios then suggest you confirm that both btle and ant+ are turned on. My polar h10 lets you turn them off to save battery life, and comes default with some off).

[Carl Watts]

Tried replacing the battery on the strap ?

Only last about a year.

I soak my strap in a tub of hot water now before putting it on.

The straps only last like 3 to 5 years then they start giving you trouble. I have one of those red Garmin HRM RUN and its as solid as a rock with the connection.

[Oldcolonial]

Thank you for the advice. Will update when I have it sorted.

[Oldcolonial]

So, upgraded the Firmware, dropped new batteries into the PM5 and changed the battery in the transmitter. It turned out to be the firmware upgrade that did the trick. The PM5 batteries tested at 1.27-9 each, so they were due. Did the battery for good measure since I had some extra 2032's and the original battery was closing in on a year.

As an aside, I had no luck upgrading the firmware with a USB drive, it only worked when I used the USB a to b cable. Now I have the problem that all my splits are much slower than they used to be. This has nothing to do with the rower though, just my lack of conditioning.

[ROWlonda]

I've been having the same issue with my Garmin HRM in the last week or so - same as you, the HR signal shows up fine on my FENIX7, but won't stay connected to the rower. C2 diagnostic tool said my PM5 was already running the latest firmware, so I ran the troubleshooter, pulled the PM5 batteries and tested them (charge level was good), and put them back in. After all that, the HRM signal held, but only for one session. Going to replace the CR battery in the strap today and see if that helps [fingers crossed].

[Carl Watts]

Connectivity issues, go strait to changing the CR2032 in the HRM strap.

It the battery is down at like 2.7V, then change it. I have had some weird Lithium battery stuff go on in the past, even if the Voltage appears ok, change it.

These batteries can cause all sorts of fun in you car remotes as well, seen instances where the battery failed in the second remote that was never used in as little as 2 years. Personally I don't think some batteries are being made properly anymore either.

[Rick]

Glad you got it sorted. My wife’s Garmin Dual HRM started acting odd like that, and a new battery fixed it. I read somewhere battery changes were difficult with the Garmins, but I did hers and mine in just a few minutes.