Change operational mode of CAN transceiver
Reading datasheets is apparently dying skill...

There is no special "wake-up pattern" that you can send. The standby mode is initiated by setting STB pin high and the transceiver will remain in it until you set it low. In this mode it cannot produce normal RX output, so you cannot "decode" any pattern.

All it does is output low level on RXD pin when it detects dominant state on a bus for longer than "T(fltr)bus", which is about 1.5 µs. This is about the length of 1 bit at 660 bps data rate.

In effect, any activity on a bus will eventually trigger RXD, allowing you to wake up the transceiver using STB pin and start receiving data.