Hi, 爱飞，
I have checked your CAN transceiver, I think there is not problem. But you have to make sure the control signals are correct.
For TJA1042 transceiver, the VIO pin should be connected to 3.3V, the STB pin should be connected to GND so that the chip work normally, the MOS control pin must turn on the 5V power supply.
For the code of CAN bus of LPC540xx family,I do not know if you use SDK, anyway, you have to power up the CAN module, enable the CAN gated clock, set the CAN TX/RX pin as CAN pins, initialize the CAN module correctly.
Hope it can help you
BR
XiangJun Rong
.png){kind=link}