SMD 3 terminal filter capacitor help

[ScottM]

I am doing a repair to an I/O board in an ECU from a Volvo excavator and need some guidance on replacing /selecting a destroyed 3 terminal pass thru filter capacitor. I'll admit I'm pushing my abilities but have little choice as replacement boards are not available and I can't justify $2000 for a used unit that might work.

So here is what I know. The ECU is an old Contronic E system and the I/O board burned a 3 terminal cap on a circuit that is the 0V point for 5 different sensors. The first component is an 1806 size 3 termianl capacitor. It was literally burned off the board. This is a 6 layer board. I do not believe the damage went below the 2 layer. I am finishing repairs and replacing the missing pad but need help selecting a replacement capacitor.

What I know is that of the 5 sensors that use this path 2 provide a variable resistance, 2 provide a variable voltage and 1 is a 4-20ma circuit. I believe the damage occurred when the oil pressure sensor which is powered with 24V was disconnected and a connection was made from unfused 24V to this 0v path. I think. I have bench tested all the sensors and am replacing the 4-20ma one as it is not consistent.

There was another capacitor right next to this that provides an 8.5v source for the 4-20ma sensor that I will also replace. out of the circuit it measures 22Kpf. The closest I can find in that package is 33Kpf rated 300ma at 100V. Is this OK and would it seem appropriate for both replacements? Other ideas?

Any thoughts are helpful. Thanks.

[floobydust]

These are for EMI filtering, and try act as a fuse if a ground fault occurs... 
Usually 1800pF-4700pF at 100-250V, not too large capacitance for fast/high impedance signals like an O2 sensor.

Look at Murata NFM feedthrough capacitors, EMI filter, and TDK YFF series.

The SMT package size is large, which will narrow down your options.