The manifold can occasionally stop broadcasting the Bluetooth address. To resolve this issue, you can disconnect the manifold connector and then reconnect it, or reboot (power cycle) the manifold. With the ignition off, pull the main fuse, and then reinsert it.
If you have an Android device and are having trouble connecting to the manifold, it has been confirmed that the FitBit app will limit Bluetooth communication between the mobile device and 3H/3P manifold. Uninstalling the FitBit App will resolve the issue. Visit the FitBit site for more details.