The voltages look odd there. Unless its an unusual CAN system (I am also not experienced on 2 wheels) the voltages look really odd 0 to 4V and 1V to 5V.
When posting waveforms can you either post the waveform or use the Edit / Copy Entire Waveform As Image command. That allows us to check the settings. As an example if you were AC coupled it could drop the voltage down to 0V, but even then it would still be odd as 4V is a big swing for CAN.
It is one thing testing resistance & another load testing !
The grounds you checked check again with the bike running with the scope as a DMM. (black to ground (Batt -)red to ground being tested))
Does the dash receive the voltage from the ECU for the engine via CAN ?
Grab a CAN capture anyway & post it on here lets have a looksy
Just so you know i am not a bike guru but a few of us may be able to help with testing methods & possible results/captures.
Robski, thanks very much re load testing grounds. yes totaly agree & thanks for showing me how to do this with the scope. tested OK
Yes, batt voltage is CAN line. I found today using texa through diag port battery voltage stays at 11VDC BUT when I switch the bike off the min/max shows as you'd expect circa 11.5/14.9VDC - so I took the CAN snapshot
Not concerned who is bike guru or not you guys are a great help and methodology is going to be very similar I would expect.
Do I check the ECU sensor grounds in the same manner? ie black to groud & red to sesnor ground? What settings do you recommend on scope for these tests?
I didn't explain myself all that well previously re the battery voltage reading as expected when ignition truned off.
What I was truing to say was this. Using my diag equiipment TEXA, reading through diag output on bike, battery volatge is like this;
bike not running, correct battery voltage
bike running, battery voltage reading stops updating until engine switched off, then min max volatge apppears and is normal. I am thinking the jumbled CAN signal is unreadable by TEXA ( and is why fault is appearing on dash )
The voltages look odd there. Unless its an unusual CAN system (I am also not experienced on 2 wheels) the voltages look really odd 0 to 4V and 1V to 5V.
When posting waveforms can you either post the waveform or use the Edit / Copy Entire Waveform As Image command. That allows us to check the settings. As an example if you were AC coupled it could drop the voltage down to 0V, but even then it would still be odd as 4V is a big swing for CAN.
Thx
Alan
Sorry Alan, just saw this. I will do that from now on.