Using an already existing output as an "Indicator"

[DerekAE86]

I don't have any other outputs available to me and I was thinking about utilizing one of the pre-configured outputs as an indication to a change in status.

For example sweeping the tacho or priming the fuel pump, etc.
I assume you could configure the engine check light to do it - but I don't have one wired up.

The specific idea I'm playing around with currently is having a push button that when held for 5s with the engine off will engage a valet mode which swaps the RPM Limit table to one that only has enough to move the car around.

But I want a way to indicate that this swap has happened - so being able to sweep the tacho or trigger a 1sec pump prime would be neat way of doing it.

However these are dedicated outputs in PCLink and I'm unsure if I can easily recreate them using a GP output with a OR statement.

[Adamw]

It will depend a bit on how complex the function that you want to interfere with is, but for your tacho example you could assign the tacho function output to a CAN aux instead of a real aux, then manipulate that CAN aux frequency in a math function or with a GP PWM 3D table etc before outputting to the tacho.