The buttons are attached to the IPC inputs. The IPC sends the signal on the data line to the PZM. PZM has separate outputs for each controlling a relay (for each). The actual supply power is fuse protected so quite a lot of things to go wrong.
Then on the other hand the Valet switch (or Key) disables both these functions so...gues what you should check first?
You can also test the buttons by accessing the IPC inputs menu, and you can test the part after the IPC by accessing the IPC overrides menu.
My on dash trunk release doesn't seem to be working. Valet mode isn't on and the fuel door opens with the dash button, but the trunk won't. I've only had it a week and have noticed that the trunk release seems iffy because it'll only work like once a day... twice if i'm lucky
Use your PZM overrides to force the trunk release output ON. This will tell you for sure if you have a issue with the controls or with the actuator.
The trunk release button grounds one input of the IPC. The IPC communicate this to the PZM to turn the trunk release output ON.
So you have to diagnose:
1. The trunk release button
2. The IPC trunk release button input (and the wiring between 1 and 2)
3. The data line between IPC and PZM (but since anything else in your car works that is fine)
4. The PZM output.
5. The trunk release actuator (and the wiring between 4 and 5).
Most likely 5 is your problem but do diagnose 1 to 5.
The IPC trunk release input is IPI01 and is found in the IPC Input Display menu(takes care of 1 and 2).
The PZM trunk release output is S01 and is found in the PZM Override menu (takes care of 5).
You can also monitor the status of the PZM output following the PZO01 in the PZM Outputs menu(takes care of 1-5).
Follow the instructions in this thread for how to access these menus (start reading from "Remember these:").