i find this:
Ensure that in addition the 1k pull-up and 1N4148 diode for the CAN interface has been added as shown in this schematic.
Resistor and diode are even required if no slave module is used!
[3d] Ensure that the D0-D3 data lines of your LCD are not connected to the core module (LCD is accessed in 4bit mode to keep the ECAN Rx/Tx pins free
i ve got a 4X20 lcd i soldered all the pins, and my core work…i 've got a doubt ,do i run it in 4 bits, for a single core and 2 sids..thanks
The official response, I believe, would be yes, you should. In practice, my LCD worked fine with all connections hooked up, but I would say there are no guarantees. If you want to do it right, I would make the changes. I plan switching to 4-bit soon myself, although I’m sort of hoping Smash might update the CORE layout to make it easier to do 
I plan switching to 4-bit soon myself…
It’s not like it’s rocket science Cut 4 leads - done.
Yes, 4bit mode is preferred.
Well, cut wires (and I think some LCDs need those to be grounded as well?), add the resistors, and, most importantly, make it look pretty My pretty multi-colored ribbon cable will be ugly and severed
In practice, my LCD worked fine with all connections hooked up, but I would say there are no guarantees.
I’ll give you a guarantee: Depending on your LCD, doing that is almost as likely to short the pins and destroy your PIC and LCD, as it is to work 
My pretty multi-colored ribbon cable will be ugly and severed
If you want it to look pretty, cut a slit along the back side of the cable with a scalpel, slide the wire out of the insulation, cut it short, and crimp the IDC onto the empty insulation. Noone will know… or better yet, wrap and heatshrink it