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This is the class2 "voltage" with ignition ON...with my scope the green trace is the class 2...0-7 volts...blue and red are a good high speed CAN bus waveform...measuring the high speed CAN in millionths of a second...extremely fast !!
Is 6 and 14 with ignition ON ??...thought you had NO ignition function ??...with ignition off you should just see some "ghost" voltage on either on !!...this is my 6 and 14 ignition ON...roughly 2.5 volt bias...with battery DISCONNECTED you should see roughly 60 ohms with one lead on 6 and other on 14.
when it acts up it has no ignition function, after it sits it’s fine, just when it’s hot it acts up.
This was tested with ignition on and cold
i saw “ghost” with ignition off.
were my readings within spec? Not as high as yours but are the acceptable?
when it acts up it has no ignition function, after it sits it’s fine, just when it’s hot it acts up.
This was tested with ignition on and cold
i saw “ghost” with ignition off.
were my readings within spec? Not as high as yours but are the acceptable?
Your CAN high and low voltages are a little low...should be close to 2.5 volts...a module may be pulling the voltage down...90% of comm issues can be solved with a volt or ohm meter...intermittent are best diagnosed with a labscope.
Your CAN high and low voltages are a little low...should be close to 2.5 volts...a module may be pulling the voltage down...90% of comm issues can be solved with a volt or ohm meter...intermittent are best diagnosed with a labscope.
You would have to remove a module and jumper the CAN high and low wires...do you have Onstar (RPO UE1) ??...for instance you can remove the ESC module which sits above the ECM and jumper pins 39 to 40 and 21 to 22...now see if you have 2.5 volts at the DLC.
