TPMS Audi A6 4F: Wake Up via CAN Bus

Hi everyone,

I'm having a small issue with the tire pressure monitoring system (TPMS) in my Audi A6 4F. According to the diagnostic readings, only 5.7V are present at 3 of the sensors. The fourth sensor shows fluctuating voltages, ranging from 0.8V, then 19V, and back down to 0V. I've already checked the wiring, and it seems to be in good condition.

I suspect the control unit is faulty. So, I removed it and want to test it using the laboratory power supply on my desk.

I've connected the positive and ground wires to the control unit, but it immediately shuts off (0A current draw). I suspect that it needs to be 'woken up' first via CAN. Could that be the issue? If so, does anyone have more information on how to do this so I can measure the output voltages on each channel with a multimeter?