E-Tube asked me to change the passkey and now it won't connect

After you change the remote e-tube passkey chances are the mobile app won’t let you connect to the bike. This is usually caused by your phone having stored or cached the previous passkey.

In order to get around this problem simply go to your phone’s bluetooth device list and “forget” the D-fly / Wireless Unit from your phone. Now you should be able to connect to the bike again and you will be prompted to enter (new) the passkey.