New di2 stuck in synch mode

[markemark]

New bike with di2 12 speed. First couple of weeks everything worked perfectly. I now seem to be stuck in full synch mode. As I rotate through the modes (double pressing the button) I cycle through the blue light being on, double flash and triple flash, but not matter which it always operates as full synch. That is when I shift the chainring, the cassette gear does not change. But if I go to 1st gear on the cassette the chain ring shifts down and the cassette shifts up 3 gears (and vice versa). Had the bike for about a month so I may be doing something wrong but I'm fairly sure the first 2 weeks I tried all 3 options and they all worked as expected.

The first weekend I connected vie phone bluetooth. I don't think I made any changes and it also worked for a couple of weeks after that so fairly sure it's not that.

The battery did get VERY low (it must have been delivered at <10% ) to the point the cassette had power to shift but the chainring didn't. I have fully it charged it. It is around this time it stopped being able to change modes but maybe be coincidence.

 

[88robb]

It sounds like the low battery may have corrupted a setting. You need to re-save your shift mode preferences.

While connected via Bluetooth, open the E-Tube app. Go to the shift mode settings. Manually set your preferred modes for each of the three light settings (blue, double flash, triple flash). Save and apply the changes to the derailleurs. This should fix it.

 

[markemark]

It sounds like the low battery may have corrupted a setting. You need to re-save your shift mode preferences.

While connected via Bluetooth, open the E-Tube app. Go to the shift mode settings. Manually set your preferred modes for each of the three light settings (blue, double flash, triple flash). Save and apply the changes to the derailleurs. This should fix it.

Thanks, yes. I should have posted yesterday but I reconnected the app and pressed apply from the original settings and it seemed to have cured it.

What’s super helpful though is your assessment as to the reason as I thought I did something wrong. But it makes sense that a nearly flat battery caused it to get confused. I’ll keep an eye on battery levels and not let it get so low in the future. Thanks.

 

[88robb]

Thanks, yes. I should have posted yesterday but I reconnected the app and pressed apply from the original settings and it seemed to have cured it.

What’s super helpful though is your assessment as to the reason as I thought I did something wrong. But it makes sense that a nearly flat battery caused it to get confused. I’ll keep an eye on battery levels and not let it get so low in the future. Thanks.

Glad that worked. And you're exactly right a low 12v battery makes the car's computers act strangely. It wasn't anything you did wrong. Keeping an eye on the battery level is a smart plan.

 

[TerryDi2]

ut if I go to 1st gear on the cassette the chain ring shifts down and the cassette shifts up 3 gears (and vice versa). Had the bike for about a month so I may be doing something wrong but I'm fairly sure the first 2 weeks I tried all 3 options and they all worked as expected.

If it's still happening, that could be Gear Position Control.

This is what GPC does:

If you're in the big ring (front) and in one of the two smallest cassette sprockets (11T / 12T) and then shift the front derailleur to the small ring, the bike will instead shift the rear derailleur. This is normal, and working as intended.

See page 19 here: https://si.shimano.com/en/pdfs/dm/RARD010/DM-RARD010-07-ENG.pdf

 

[markemark]

If it's still happening, that could be Gear Position Control.

This is what GPC does:

If you're in the big ring (front) and in one of the two smallest cassette sprockets (11T / 12T) and then shift the front derailleur to the small ring, the bike will instead shift the rear derailleur. This is normal, and working as intended.

See page 19 here: https://si.shimano.com/en/pdfs/dm/RARD010/DM-RARD010-07-ENG.pdf

Thank you. I think as @88robb suggested, the system setting got corrupted as the power was virtually out. Once I re applied from the app it all seems to be working fine for a few rides.