# ADU, Can2Usb - says disconnected **URL:** \ **Category:** ADU\ **Created:** [April 29, 2025, 6:31pm UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603 "2025-04-29T18:31:14Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 29, 2025, 6:31pm UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/1 "2025-04-29T18:31:14Z")
So I wired in my display including the CanBus wiring from my Ecu. I plugged the Ecu CanBus connector to the Usb2Can and the green light flashes and the orange light flashes. The manual says that this means the Usb2Can is working (green flashing) and ‘Data transfer’ (orange flashing) on the CanBus channel. On the ADU software it says ‘Can 1 - OK’ but shows Disconnected in the bottom left of the screen (Flashing Red). ![connection2](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/9/91005ee82c87d3f5335388a2c9e7ebdcdfa7e2a5.jpeg) ![connection1](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/d/da187df4f209103aa585b1f77b98ff726180447b.jpeg) My obvious thought is, how can the dash communicate via my Ecu CanBus when the preloaded software isn’t configured for it? And how would I get around this when I can’t connect to it? I am using an Emerald K6 Ecu. ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 29, 2025, 8:54pm UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/2 "2025-04-29T20:54:07Z")
Or do I need to unplug my Ecu to be able to access the Adu via the canbus without the Ecu first? Like this ![Screenshot_20250429_215514_Samsung Notes](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/9/917bd8f298f08314337ba60cdd1b3f729a7b8501.jpeg) So I’d just have laptop to Usb2Can to Adu. This is essentially what I have at the moment only with an Emerald K6 ecu instead of the EMU Black shown here ![Screenshot_20250429_215502_Samsung Notes](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/b/b1bf022f05706ea529961f19c97f3270926c280e.jpeg) ---
**Author:** ![Greg](https://avatars.discourse-cdn.com/v4/letter/g/71c47a/32.png) [@Greg](https://community.ecumaster.com/u/Greg)\ **Post date:** [April 30, 2025, 6:09am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/3 "2025-04-30T06:09:50Z")
Wrong can bus speed at ecu or wiring at ecu ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 6:38am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/4 "2025-04-30T06:38:02Z")
Thanks Greg for the reply. The Emerald K6 CanBus info is as follows: ![CanBus K6](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/5/5fc012c8ee174f4cf01fed3a361e1d16aed7c7c7.jpeg) ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 6:38am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/5 "2025-04-30T06:38:34Z")
This should mean it connects via CanBus1 automatically shouldnt it? Do you know what the ‘Canbus 1 - Ok’ is telling me exactly? ---
**Author:** ![mfudala\_ECUMASTER](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@mfudala\_ECUMASTER](https://community.ecumaster.com/u/mfudala_ECUMASTER)\ **Post date:** [April 30, 2025, 6:59am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/6 "2025-04-30T06:59:44Z")
Those statuses are described in the ADU manual (latest 111 version, pages 55–56, chapter 4). **I encourage you to read it.** Have you tried establishing a connection between the ADU client and the device with your ECU disconnected from ADU CAN1? ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 7:25am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/7 "2025-04-30T07:25:42Z")
Hi mfudala, thanks for the reply. I have read that section of the manual but given the connection states ‘Can1 OK’ I was trying to ascertain if this means that the CanBus connection is in fact ok and therefore the issue lies elsewhere. In answer to your question, I have not tried it yet without the Ecu connected as I’ll need to add in a resistor it its place as the Ecu has an internal 120 ohm resistor for the Canbus and I’m not sure I have one. ---
**Author:** ![mfudala\_ECUMASTER](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@mfudala\_ECUMASTER](https://community.ecumaster.com/u/mfudala_ECUMASTER)\ **Post date:** [April 30, 2025, 7:29am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/8 "2025-04-30T07:29:55Z")
USB to CAN has a built-in switchable resistor. Just disconnect your ECU from the CAN bus and enable the resistor in the USB to CAN adapter. The other way is to open Ecumaster Light Client and check which frames are present on the bus. There might be some that interfere with the connection between the ADU Client and the device. ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 7:38am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/9 "2025-04-30T07:38:23Z")
Thanks again for the reply but I can’t do that. My Ecu Can connector is a ‘Male’ plug socket the same as that on the Usb to Can adapter. ---
**Author:** ![Greg](https://avatars.discourse-cdn.com/v4/letter/g/71c47a/32.png) [@Greg](https://community.ecumaster.com/u/Greg)\ **Post date:** [April 30, 2025, 8:05am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/10 "2025-04-30T08:05:53Z")
make sure is connected properly on pin 1 and 2 on emerald pin 1 is can H and pin 2 is can L we have many customers using this with emerald so is not an issue with adu ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 8:10am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/11 "2025-04-30T08:10:47Z")
Hi again Mfudala, I disconnected the Ecu, measured the pins at the ADU connector and had 120 ohms and the same at the end of the CanBus connector so tried it and it worked. Connected 1st time. I then uploaded my saved ‘offline’ setup and made this permanent. Then powered off, reconnected the Ecu, and tried again and it worked without issue. Seems odd but it is working normally now. Be interested on your thoughts as to what might be going on. ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 8:12am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/12 "2025-04-30T08:12:26Z")
> [@Greg](#): > > make sure is connected properly on pin 1 and 2 on emerald pin 1 is can H and pin 2 is can L we have many customers using this with emerald so is not an issue with adu Thanks Greg, yes made sure of that but I have only recently had to replace my dash with the ADU from using a Race Technology Dash 2 Pro on which the CanBus was working fine so I was confident the CanBus wiring wasn’t the issue. ---
**Author:** ![Jcdek](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jcdek](https://community.ecumaster.com/u/Jcdek)\ **Post date:** [April 30, 2025, 8:22am UTC](https://community.ecumaster.com/t/adu-can2usb-says-disconnected/3603/13 "2025-04-30T08:22:38Z")
Thanks again to both of you for your replies and assistance. 👍