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:").