lin bus

I put the 1nF capacitor for ESD protection in the LIN interface node. After testing 6kV, impedance deterioration before and after was measured in the measurements. Does this mean that insufficient capacitance values are likely to be applied?

I will start with the fact that I have little to know knowledge of building circuits. I am in fact looking for someone that is willing to essentially draw me a wiring diagram and even better list of parts needed. I am building a breakout box for an automotive OBD2 DLC. What I am wanting to do...