Sporadic problems connecting CANtact to can bus

[madsbertelsen]

When following the guide for connecting using SocketCAN It only works around 50% of the time.
Laptop is running ubuntu 16..

when executing:
sudo slcand -o -c -s6 /dev/ttyACM0 can0
(with correct device)
Sometimes the red light (D2) will start blinking and I can subsequently do
sudo ifconfig can0 up
and
cansniffer can0
and I can see a lot of communication from can bus.

But often the red light never starts blinking and I when that happens I never see can bus communication.

I don't understand what is causing this sporadic behaviour - please help.

[inspector71]

Completely out of nowhere, and I'm almost certainly not helping, but is the car moving when you're trying to access the data?

I only mention this because the Mazda infotainment systems disallow certain actions when the car's moving. Perhaps that correlates to fifty percent of your experience? Unlikely, I know.