If not, can I pull-up with 10KR resistance external?
Hi,
No, there is no internal pull-up or pull-down inside the RXD pin of the TJA1043T, pin RXD reflects the CAN Receiver value, if this is not happening, then an error is occurring.
Typically, this pin is directly connected to the uC without the need of an external pull-up.
If you are asking this because you need smooth the edges at bit transitions, I guess it would be better to use an up to 1 kΩ series resistor of on pin TXD.
Regards,
Jose Reyes