Usbtocan adapters not sending on active bus

I have a usb can adapter and it worked fine to send data to my s7 ecu in my gutted e90 for calibration switch inputs. Im at it again with an e60 this time and when the car is off realdash sends can no problem. When the car is running the usbto can blinks on tx but nothing comes out.
Realdash can logger sees it but my other sniffer doesn’t its clearly not getting out on the bus.

Iam guessing its sending as recesive? Any way around this?

Hard to say remotely what could be the issue. Maybe the CAN speed or protocol is different on E60 than E90. Also, check the resistance of the CAN bus if you need to enable/disable the build-in resistor on the adapter.

the pt can bus is sitting around 58ohms so all good there. realdash reads can fine. the difrences between e90 can and e60 or any e chasis bmw are slim besides the 7 series, thats a monster i havent tinkered with. they use kwp2000 its standard 11bit identifier.

the e90 is a tin canned 1172hp race car very few modules are retained and can trafic is extrmely light because of this.

the e60 is a di delete 19t twin turbo car with a syvecs s7plus and a 8hp swap using turbo lamik. it has all the creature comforts and a very busy can bus.

real dash sends can when the bus trafic is low. for ex. door open car woken up. but when the car is started the tx light flashes like its sending but never gets out on the bus. im able to use a arduino with a can hat to confirm the bus is fine. seems like a problem with realdash and the usb2can adapter?

or the usb2can adapter itself. its set to normal mode and from my understanding should send ack bits but it shows the message in real dash can monitor but not on the busy bus. seems like when conected to real dash if the message is pushed back because the message isnt high priorty its not transmisted on the bus.

Thanks for the detailed info.

By usb2can adapter you mean the ‘seeedstudio’ style adapter? By its spec, there is no priority information on sent CAN frames at all, so it cannot be controlled by RealDash. If the TX light flashes, the frame goes out from the RealDash to CAN adapter, so I don’t know what I could do about it, sorry :frowning:

Understandable. Seems like the seedstudio peice isnt up to the task for a busy network.

Are GVRET or LWWICEL can units supported?

Here is a list of supported CAN adapters:

RealDash | Manuals | Supported CAN/LIN Adapters

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