Introduction
The Bluetooth version of the EcuTek Vehicle Interface (EVI-BT for short) allows to establish a wireless connection to a mobile device, such as a smartphone or tablet.
The connection process is different depending on the device type. Here are the details that are important to understand while troubleshooting connectivity issues.
How it works
iOS devices (iPhone and iPad)
In order to be used with an iOS device, the EVI-BT must behave as an iOS accessory. The key point about iOS accessories is that they normally initiate the connection to the iOS device, not vice-versa.
The first time one wants to use the EVI-BT with an iOS device, it needs to be paired. This can be done either from the system Settings > Bluetooth menu or from within the app during the on-boarding procedure that appears the first time the app is run after installing it.
Once the pairing is completed, the connection is established immediately. After that, the devices will remain connected until the link gets interrupted for some reason (ie. device moves out of range, gets powered off or its Bluetooth gets disabled).
When the EVI-BT is not connected, it will switch to a low power mode (sleep, led glowing green every 5 seconds) and will periodically attempt to reconnect to the iOS device.
The EVI-BT will only attempt to reconnect to the latest device it has been connected to. Please see the remarks in the section "Using the EVI-BT with multiple devices".
When the EVI-BT is connected to the iOS device, the "My car" button in the ECU Connect app will be enabled. If there is no connection, the button will be disabled.
Android devices
When the EVI-BT is used with Android devices, the connection is always initiated by the Android device.
The first time one wants to use the EVI-BT with the Android device, it needs to be paired. This can be done from the system Settings > Bluetooth menu.
Once the device is paired, tapping the "My car" button in the ECU Connect app will initiate the connection. The devices will remain connected until the user navigates back to the main menu or the link gets interrupted for some reason (ie. device moves out of range, gets powered off or its Bluetooth gets disabled).
Remarks
Using the EVI-BT with multiple devices
The EVI-BT can be used with any number of devices. Only a single device can be connected at the time.
If one of them is an iOS device, after the EVI-BT has been connected to a different device, the EVI-BT has to be manually connected from the iOS device Settings > Bluetooth menu. It won't be possible to use the EVI-BT from the ECU Connect app until it gets connected (the "My car" button will be disabled).
Using the EVI-BT with other OBD cables
It is not possible to use at the same time the EVI-BT and other EcuTek or third party OBD cables/dongles.
In particular, using an OBD Y-splitter cable to connect both the EVI-BT and a third-party dongle to the vehicle OBD port, will produce unpredictable results.