High impedance continuity check circuit


I’m looking vor a circuit that allows me to check a wire for continuity.
The Output should be connected to an Input pin of an Controller.

The Goal is it to measure the continuity of the cables from our measurement Equipment to the test connector.
If anyhow possible the actual measurement/Signal channel (which ranges from turned off power Outputs to CAN and LIN Transceivers) should not be disconnected for testing and one end of the continuity check probes should be connected at all times.
The only Thing that would be switched is the 2nd end of the probe to the end of the cable.
Alternatively we could Switch the 1st end of the probe too, but it should not respond to any Signal that might come out of the measurement channel (CAN, LIN, …)
These channels will not be at use at this time, but I can not Change them anymore.
Also the test voltage from the probe must not damage any of the measurement electronics.

Any ideas?
I came accross this,
but have no idea if this would work.