New-to me 2012.5; the frunk has been popped in the morning when I go to drive off. Only happens overnight (dew?). Seems to do it by itself, and doesn't matter if the car is locked or not.

Any ideas?

 

Where is the key when this happens?

 

In the house, hanging on a key holder ~50' away (car port)

 

Any rodent activity?

 

I saw that when my battery died... Check yours ? (as in real test)

 

Always possible; but how would it trigger? It has happened about 4-5 times in the last week

hmmm.. indy mechanic just said battery was good ~3 weeks ago.

 

Chewing wires = good way to get intermittent electrical gremlins.

 

Sounds like a battery gremlin. How old is the battery. I know these batteries will show decent voltage with 5-6 years on them but you could start to get these types of ghosts.

 

I would guess battery as well. Makes sense that the car would open the trunk if the battery is dying. Go get your battery checked for free and if you need to replace it have that done.

 

Page 3,057 of the .1 Factory Service Manual floating around seems to have the circuit diagram for the frunk actuator. Maybe take a look at the components for wire damage, or pinching/crimping of the cables, in the areas mentioned in the diagram?

 

OP said his indy checked the battery 3 weeks ago and it was good.

 

Wasn't sure if that diagram was legible, here is a snapshot of just the actuator circuit. I'd be tracing the black/brown wire from the Front End Control Unit, right side of the luggage compartment, to the Luggage Compartment Lid Actuator.

I'm not sure if this is physically accessible, but you could also check the Brown wire for correct ground i.e. zero potential from the wire to a known ground point on the chassis somewhere.

Lastly, I'd stick a meter on the output of the front end control unit terminal 39 brn/blk and actuate the trunk release. If it's correct that it provides 12V to the trunk release solenoid, then checking terminal 39 has a good solid 12V would confirm the actuator circuit is behaving properly.

If I have the logic wrong (and I might), and the switching part of this is on the ground side (i.e. any switched or otherwise ground on the actuator activates it) then an errant ground will trip the solenoid. In this case, I'd focus on the ground wires and make sure the mount of the actuator itself is not corroded or otherwise providing an unexpected path to ground for the 12V. If you had this, you'd get intermittent operation of the trunk solenoid at times, and the result would be the trunk would pop open.

Bear in mind this is just guesswork from looking at the diagram and trying to figure out how this might work; I'm for sure no tech.

 

This is great; thank you! Might be some time until I can take apart panels to trace it.

 

So, looks like there is something wrong with the front-end electronics control unit -- I am throwing code c12016 (Communications with front-end electronics control unit). The wiring diagram shows that being the core unit for controlling the frunk.

 

That thing looks like it's on the CAN bus. (Not sure if you are familiar, but CAN (controller area network) is a very heavily used industry standard in Germany for automotive buses / communications. Please forgive me if you know this already; I only say that to explain this comment

Can you locate the FECU and unplug then reseat the CAN bus connector? Might be just a bit of carbon build up or other schmutz on the connector pins. Be an idea to hose it all down with some contact cleaner while you have it apart.