ditto.
also, are there any aftermarket pin switches visible anywhere in the hatch area.
Double and tripple check those and get back here with your info.
If you don't have an alarm and there are no pin switches, then we need more info to help diagnose the problem like these:
1. Do any dish lights come on and stay on.....such as check engine, or rear hatch/door ajar indicator? If the CEL comes on, pull the codes and post them here.
2. What all works electrically and what doesn't? Do the headlights work, interior lights, radio, brake lights, reverse lights, horn, cig. lighter, etc. Post exactly what works and what doesn't.
3. What year and model teggy do you have and is it auto/manual?
Just FYI, about the only thing wires the rear hatch has in common with the engine or ECU are the brake switch (used for helping to control RPM under braking and for the brake lights, and the reverse lights if you have an auto and that would only be affected through the TCU and shouldn't affect engine running conditions.
It is possible that the ELD is acting up, but if your headlights don't kill the car and your trunk opening does, then I seriously doubt that's it.
Double and triple check for an alarm and pin switch in the trunk hatch area. I'd be willing to bet that's the culprit.