Your information seems to be confusing. First, LIN does not work w/ pwm signals on LIN data line. Maybe it could be SAE J1850. Second, it is strange to me hear that one sensor is a master and another is a slave. Normally the master is an ECU connected to a CAN network.
Before desperate attempts, try to get more info on your particular system.
If it is really LIN and if you just really need a wake up, it is quite easy, just drop the LIN line low for at least 150us.
I hope it helps.
Cheers,
Celso